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Sample records for geysers steam field

  1. Gas and Isotope Geochemistry of 81 Steam Samples from Wells in The Geysers Geothermal Field, Sonoma and Lake Counties, California

    Science.gov (United States)

    Lowenstern, Jacob B.; Janik, Cathy J.; Fahlquist, Lynne; Johnson, Linda S.

    1999-01-01

    The Geysers geothermal field in northern California, with about 2000-MW electrical capacity, is the largest geothermal field in the world. Despite its importance as a resource and as an example of a vapor-dominated reservoir, very few complete geochemical analyses of the steam have been published (Allen and Day, 1927; Truesdell and others, 1987). This report presents data from 90 steam, gas, and condensate samples from wells in The Geysers geothermal field in northern California. Samples were collected between 1978 and 1991. Well attributes include sampling date, well name, location, total depth, and the wellhead temperature and pressure at which the sample was collected. Geochemical characteristics include the steam/gas ratio, composition of noncondensable gas (relative proportions of CO2, H2S, He, H2, O2, Ar, N2, CH4, and NH3), and isotopic values for deltaD and delta18O of H2O, delta13C of CO2, and delta34S of H2S. The compilation includes 81 analyses from 74 different production wells, 9 isotopic analyses of steam condensate pumped into injection wells, and 5 complete geochemical analyses on gases from surface fumaroles and bubbling pools. Most samples were collected as saturated steam and plot along the liquid-water/steam boiling curve. Steam-togas ratios are highest in the southeastern part of the geothermal field and lowest in the northwest, consistent with other studies. Wells in the Northwest Geysers are also enriched in N2/Ar, CO2 and CH4, deltaD, and delta18O. Well discharges from the Southeast Geysers are high in steam/gas and have isotopic compositions and N2/Ar ratios consistent with recharge by local meteoric waters. Samples from the Central Geysers show characteristics found in both the Southeast and Northwest Geysers. Gas and steam characteristics of well discharges from the Northwest Geysers are consistent with input of components from a high-temperature reservoir containing carbonrich gases derived from the host Franciscan rocks. Throughout the

  2. Development of an Enhanced Two-Phase Production System at the Geysers Geothermal Field; FINAL

    International Nuclear Information System (INIS)

    Steven Enedy

    2001-01-01

    A method was developed to enhance geothermal steam production from two-phase wells at THE Geysers Geothermal Field. The beneficial result was increased geothermal production that was easily and economically delivered to the power plant

  3. The Geysers Geothermal Field Update1990/2010

    Energy Technology Data Exchange (ETDEWEB)

    Brophy, P.; Lippmann, M.; Dobson, P.F.; Poux, B.

    2010-10-01

    view across all technical fields, as related to The Geysers steam-dominated geothermal system. The Geysers has seen many fundamental changes between 1990-2010 and yet the geothermal resource seems still to be robust to the extent that, long after its anticipated life span, we are seeing new geothermal projects being developed on the north and west peripheries of the field. It is hoped that this report provides a focused data source particularly for those just starting their geothermal careers, as well as those who have been involved in the interesting and challenging field of geothermal energy for many years. Despite many hurdles The Geysers has continued to generate electrical power for 50 years and its sustainability has exceeded many early researchers expectations. It also seems probable that, with the new projects described above, generation will continue for many years to come. The success of The Geysers is due to the technical skills and the financial acumen of many people, not only over the period covered by this report (1990-2010), but since the first kilowatt of power was generated in 1960. This Special Report celebrates those 50 years of geothermal development at The Geysers and attempts to document the activities that have brought success to the project so that a permanent record can be maintained. It is strongly hoped and believed that a publication similar to this one will be necessary in another 20 years to document further activities in the field.

  4. Compilation of gas geochemistry and isotopic analyses from The Geysers geothermal field: 1978-1991

    Science.gov (United States)

    Lowenstern, Jacob B.; Janik, Cathy; Fahlquist, Lynne; Johnson, Linda S.

    1999-01-01

    We present 45 chemical and isotopic analyses from well discharges at The Geysers geothermal field and summarize the most notable geochemical trends. H2 and H2S concentrations are highest in the Southeast Geysers, where steam samples have δD and δ18O values that reflect replenishment by meteoric water. In the Northwest Geysers, samples are enriched in gas/steam, CO2, CH4, and N2/Ar relative to the rest of the field, and contain steam that is elevated in δD and δ18O, most likely due to substantial contributions from Franciscan-derived fluids. The δ13C of CO2, trends in CH4 vs. N2, and abundance of NH3 indicate that the bulk of the non-condensable gases are derived from thermal breakdown of organic materials in Franciscan meta-sediments.

  5. The impact of injection on seismicity at The Geysers, California Geothermal Field

    OpenAIRE

    Majer, Ernest L.; Peterson, John E.

    2007-01-01

    Water injection into geothermal systems has often become a required strategy to extend and sustain production of geothermal resources. To reduce a trend of declining pressures and increasing non-condensable gas concentrations in steam produced from The Geysers, operators have been injecting steam condensate, local rain and stream waters, and most recently treated wastewater piped to the field from neighboring communities. If geothermal energy is to provide a significant increase in energy in ...

  6. Analysis of induced seismicity at The Geysers geothermal field, California

    Science.gov (United States)

    Emolo, A.; Maercklin, N.; Matrullo, E.; Orefice, A.; Amoroso, O.; Convertito, V.; Sharma, N.; Zollo, A.

    2012-12-01

    Fluid injection, steam extraction, and reservoir stimulation in geothermal systems lead to induced seismicity. While in rare cases induced events may be large enough to pose a hazard, on the other hand the microseismicity provides information on the extent and the space-time varying properties of the reservoir. Therefore, microseismic monitoring is important, both for mitigation of unwanted effects of industrial operations and for continuous assessment of reservoir conditions. Here we analyze induced seismicity at The Geysers geothermal field in California, a vapor-dominated field with the top of the main steam reservoir some 1-3 km below the surface. Commercial exploitation began in the 1960s, and the seismicity increased with increasing field development. We focus our analyses on induced seismicity recorded between August 2007 and October 2011. Our calibrated waveform database contains some 15000 events with magnitudes between 1.0 and 4.5 and recorded by the LBNL Geysers/Calpine surface seismic network. We associated all data with events from the NCEDC earthquake catalog and re-picked first arrival times. Using selected events with at least 20 high-quality P-wave picks, we determined a minimum 1-D velocity model using VELEST. A well-constrained P-velocity model shows a sharp velocity increase at 1-2 km depth (from 3 to 5 km/s) and then a gradient-like trend down to about 5 km depth, where velocities reach values of 6-7 km/s. The station corrections show coherent, relatively high, positive travel time delays in the NW zone, thus indicating a strong lateral variation of the P-wave velocities. We determined an average Vp-to-Vs ratio of 1.67, which is consistent with estimates from other authors for the same time period. The events have been relocated in the new model using a non-linear probabilistic methods. The seismicity appears spatially diffused in a 15x10 km2 area elongated in NW-SE direction, and earthquake depths range between 0 and 6 km. As in previous

  7. Three-dimensional numerical reservoir simulation of the EGS Demonstration Project at The Geysers geothermal field

    Science.gov (United States)

    Borgia, Andrea; Rutqvist, Jonny; Oldenburg, Curt M.; Hutchings, Lawrence; Garcia, Julio; Walters, Mark; Hartline, Craig; Jeanne, Pierre; Dobson, Patrick; Boyle, Katie

    2013-04-01

    The Enhanced Geothermal System (EGS) Demonstration Project, currently underway at the Northwest Geysers, California, aims to demonstrate the feasibility of stimulating a deep high-temperature reservoir (up to 400 °C) through water injection over a 2-year period. On October 6, 2011, injection of 25 l/s started from the Prati 32 well at a depth interval of 1850-2699 m below sea level. After a period of almost 2 months, the injection rate was raised to 63 l/s. The flow rate was then decreased to 44 l/s after an additional 3.5 months and maintained at 25 l/s up to August 20, 2012. Significant well-head pressure changes were recorded at Prati State 31 well, which is separated from Prati 32 by about 500 m at reservoir level. More subdued pressure increases occur at greater distances. The water injection caused induced seismicity in the reservoir in the vicinity of the well. Microseismic monitoring and interpretation shows that the cloud of seismic events is mainly located in the granitic intrusion below the injection zone, forming a cluster elongated SSE-NNW (azimuth 170°) that dips steeply to the west. In general, the magnitude of the events increases with depth and the hypocenter depth increases with time. This seismic cloud is hypothesized to correlate with enhanced permeability in the high-temperature reservoir and its variation with time. Based on the existing borehole data, we use the GMS™ GUI to construct a realistic three-dimensional (3D) geologic model of the Northwest Geysers geothermal field. This model includes, from the top down, a low permeability graywacke layer that forms the caprock for the reservoir, an isothermal steam zone (known as the normal temperature reservoir) within metagraywacke, a hornfels zone (where the high-temperature reservoir is located), and a felsite layer that is assumed to extend downward to the magmatic heat source. We then map this model onto a rectangular grid for use with the TOUGH2 multiphase, multicomponent, non

  8. Back-Projection Imaging of extended, high-frequency pre-, co-, and post-eruptive seismicity at El Jefe Geyser, El Tatio Geyser Field, Chile

    Science.gov (United States)

    Kelly, C. L.; Lawrence, J. F.; Beroza, G. C.

    2017-12-01

    El Tatio Geyser Field in northern Chile is the third largest geyser field in the world. It is comprised of 3 basins that span 10 km x 10 km at an average elevation of 4250 m and contains at least 80 active geysers. Heavy tourist traffic and previous geothermal exploration make the field relatively non-pristine and ideal for performing minimally invasive geophysical experiments. We deployed a dense array of 51 L-28 3-component geophones (1-10 m spacing, corner frequency 4.5 Hz, 1000 Hz sample rate), and 6 Trillium 120 broadband seismometers (2-20 m spacing, long period corner 120 s, 500 Hz sample rate) in a 50 m x 50 m grid in the central Upper Geyser Basin (the largest basin in area at 5 km x 5 km) during October 2012 as part of a collaborative study of hydrothermal systems between Stanford University; U.C. Berkeley; U. of Chile, Santiago; U. of Tokyo; and the USGS. The seismic array was designed to target at El Jefe Geyser (EJG), a columnar geyser (eruption height 1-1.5 m) with a consistent periodic eruption cycle of 132 +/- 3 s. Seismicity at EJG was recorded continuously for 9 days during which 6000 total eruptions occurred. Excluding periods of high anthropogenic noise (i.e. tourist visits, field work), the array recorded 2000 eruptions that we use to create 4D time-lapse images of the evolution of seismic source locations before, during and after EJG eruptions. We use a new back-projection processing technique to locate geyser signals, which tend to be harmonic and diffuse in nature, during characteristic phases of the EJG eruption cycle. We obtain Vp and Vs from ambient-field tomography and estimates of P and S propagation from a hammer source recorded by the array. We use these velocities to back-project and correlate seismic signals from all available receiver-pairs to all potential source locations in a subsurface model assuming straight-line raypaths. We analyze results for individual and concurrent geyser sources throughout an entire EJG eruption cycle

  9. Testing for the ‘predictability’ of dynamically triggered earthquakes in Geysers Geothermal Field

    Science.gov (United States)

    Aiken, Chastity; Meng, Xiaofeng; Hardebeck, Jeanne L.

    2018-01-01

    The Geysers geothermal field is well known for being susceptible to dynamic triggering of earthquakes by large distant earthquakes, owing to the introduction of fluids for energy production. Yet, it is unknown if dynamic triggering of earthquakes is ‘predictable’ or whether dynamic triggering could lead to a potential hazard for energy production. In this paper, our goal is to investigate the characteristics of triggering and the physical conditions that promote triggering to determine whether or not triggering is in anyway foreseeable. We find that, at present, triggering in The Geysers is not easily ‘predictable’ in terms of when and where based on observable physical conditions. However, triggered earthquake magnitude positively correlates with peak imparted dynamic stress, and larger dynamic stresses tend to trigger sequences similar to mainshock–aftershock sequences. Thus, we may be able to ‘predict’ what size earthquakes to expect at The Geysers following a large distant earthquake.

  10. Testing for the 'predictability' of dynamically triggered earthquakes in The Geysers geothermal field

    Science.gov (United States)

    Aiken, Chastity; Meng, Xiaofeng; Hardebeck, Jeanne

    2018-03-01

    The Geysers geothermal field is well known for being susceptible to dynamic triggering of earthquakes by large distant earthquakes, owing to the introduction of fluids for energy production. Yet, it is unknown if dynamic triggering of earthquakes is 'predictable' or whether dynamic triggering could lead to a potential hazard for energy production. In this paper, our goal is to investigate the characteristics of triggering and the physical conditions that promote triggering to determine whether or not triggering is in anyway foreseeable. We find that, at present, triggering in The Geysers is not easily 'predictable' in terms of when and where based on observable physical conditions. However, triggered earthquake magnitude positively correlates with peak imparted dynamic stress, and larger dynamic stresses tend to trigger sequences similar to mainshock-aftershock sequences. Thus, we may be able to 'predict' what size earthquakes to expect at The Geysers following a large distant earthquake.

  11. Imaging Seismic Source Variations Using Back-Projection Methods at El Tatio Geyser Field, Northern Chile

    Science.gov (United States)

    Kelly, C. L.; Lawrence, J. F.

    2014-12-01

    During October 2012, 51 geophones and 6 broadband seismometers were deployed in an ~50x50m region surrounding a periodically erupting columnar geyser in the El Tatio Geyser Field, Chile. The dense array served as the seismic framework for a collaborative project to study the mechanics of complex hydrothermal systems. Contemporaneously, complementary geophysical measurements (including down-hole temperature and pressure, discharge rates, thermal imaging, water chemistry, and video) were also collected. Located on the western flanks of the Andes Mountains at an elevation of 4200m, El Tatio is the third largest geyser field in the world. Its non-pristine condition makes it an ideal location to perform minutely invasive geophysical studies. The El Jefe Geyser was chosen for its easily accessible conduit and extremely periodic eruption cycle (~120s). During approximately 2 weeks of continuous recording, we recorded ~2500 nighttime eruptions which lack cultural noise from tourism. With ample data, we aim to study how the source varies spatially and temporally during each phase of the geyser's eruption cycle. We are developing a new back-projection processing technique to improve source imaging for diffuse signals. Our method was previously applied to the Sierra Negra Volcano system, which also exhibits repeating harmonic and diffuse seismic sources. We back-project correlated seismic signals from the receivers back to their sources, assuming linear source to receiver paths and a known velocity model (obtained from ambient noise tomography). We apply polarization filters to isolate individual and concurrent geyser energy associated with P and S phases. We generate 4D, time-lapsed images of the geyser source field that illustrate how the source distribution changes through the eruption cycle. We compare images for pre-eruption, co-eruption, post-eruption and quiescent periods. We use our images to assess eruption mechanics in the system (i.e. top-down vs. bottom-up) and

  12. Partitioning geochemistry of arsenic and antimony, El Tatio Geyser Field, Chile

    Energy Technology Data Exchange (ETDEWEB)

    Landrum, J.T. [Department of Geological Sciences, The University of Texas, Austin, TX 78759 (United States); Bennett, P.C., E-mail: pbennett@mail.utexas.edu [Department of Geological Sciences, University of Texas, Austin, TX 78759 (United States); Engel, A.S. [Department of Geology and Geophysics, Louisiana State University, Baton Rouge, LA 70803 (United States); Alsina, M.A.; Pasten, P.A. [Departamento de Ingenieria Hidraulica y Ambiental, Pontificia Universidad Catolica de Chile, Santiago (Chile); Milliken, K. [Department of Geological Sciences, University of Texas, Austin, TX 78759 (United States)

    2009-04-15

    The abundance of As and Sb in aqueous, mineral and biological reservoirs was examined at El Tatio Geyser Field, a unique hydrothermal basin located in the Atacama Desert region of Chile. Here the concentration of total As and Sb in hydrothermal springs and discharge streams are the highest reported for a natural surface water, and the geyser basin represents a significant source of toxic elements for downstream users across Region II, Chile. The geyser waters are near neutral Na:Cl type with {approx}0.45 and 0.021 mmol L{sup -1} total As and Sb, respectively, primarily in the reduced (III) redox state at the discharge with progressive oxidation downstream. The ferric oxyhydroxides associated with the microbial mats and some mineral precipitates accumulate substantial As that was identified as arsenate by XAS analysis (>10 wt% in the mats). This As is easily mobilized by anion exchange or mild dissolution of the HFO, and the ubiquitous microbial mats represent a significant reservoir of As in this system. Antimony, in contrast, is not associated with the mineral ferric oxides or the biomats, but is substantially enriched in the silica matrix of the geyserite precipitates, up to 2 wt% as Sb{sub 2}O{sub 3}. Understanding the mobility and partitioning behavior of these metalloids is critical for understanding their eventual impact on regional water management.

  13. Reservoir Changes Derived from Seismic Observations at The Geysers Geothermal Field, CA, USA

    Science.gov (United States)

    Gritto, R.; Jarpre, S.

    2012-04-01

    Induced seismicity associated with the exploitation of geothermal fields is used as a tool to characterize and delineate changes associated with injection and production of fluids from the reservoir. At the same time public concern of felt seismicity has led to objections against the operation of geothermal reservoirs in close proximity to population centers. Production at the EGS sites in Basel (Switzerland) was stopped after renewed seismicity caused concern and objection from the public in the city. Operations in other geothermal reservoirs had to be scaled back or interrupted due to an unexpected increase in seismicity (Soultz-sous-forêt, France, Berlín, El Salvador). As a consequence of these concerns and in order to optimize the use of induced seismicity for reservoir engineering purposes, it becomes imperative to understand the relationship between seismic events and stress changes in the reservoir. We will address seismicity trends at The Geysers Geothermal Reservoir, CA USA, to understand the role of historical seismicity associated with past injection of water and/or production of steam. Our analysis makes use of a comprehensive database of earthquakes and associated phase arrivals from 2004 to 2011. A high-precision sub-set of the earthquake data was selected to analyze temporal changes in seismic velocities and Vp/Vs-ratio throughout the whole reservoir. We find relatively low Vp/Vs values in 2004 suggestive of a vapor dominated reservoir. With passing time, however, the observed temporal increase in Vp/Vs, coupled with a decrease in P- and S-wave velocities suggests the presence of fluid-filled fractured rock. Considering the start of a continuous water injection project in 2004, it can be concluded that the fluid saturation of the reservoir has successfully recovered. Preliminary results of 3-D velocity inversions of seismic data appear to corroborate earlier findings that the lowest Vp/Vs estimates are observed in the center of the reservoir

  14. Selecting, engineering and constructing drilling sites at the Geysers geothermal field. Geysers chinetsu ryoiki ni okeru kussaku shikichi no sentei engineering kochiku

    Energy Technology Data Exchange (ETDEWEB)

    1993-04-01

    This paper describes some examples of selection, engineering and construction of drilling sites at the Geysers geothermal field in the northern district of California State. Steep landform, thin-layered soil and violent rainfall create unstable conditions bringing about numerous landslide in the field. Selection of a well drilling site appropriate in such conditions is started by analyzing the aerial photographs by technical staff. After site selection, prospecting and soil test are conducted and a working plan in the well site is decided to prepare engineering drawings. In the construction, land preparation, the open-cutting of base-line trench, etc. are carried out. The base-line trench is a large and sufficiently deep one which is open-cut to the front end or the middle of the bottom part of the well plateau. The final construction work is to build a leading casing for interpolating cementing. The well site construction in the Geysers geothermal field is done in consideration of protecting human life, health and properties. 1 fig.

  15. Geysers advanced direct contact condenser research

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, J.; Bahning, T.; Bharathan, D.

    1997-12-31

    The first geothermal application of the Advanced Direct Contact Condenser (ADCC) technology developed by the National Renewable Energy Laboratory (NREL) is now operational and is being tested at The Geysers Power Plant Unit 11. This major research effort is being supported through the combined efforts of NREL, The Department of Energy (DOE), and Pacific Gas and Electric (PG&E). NREL and PG&E have entered into a Cooperative Research And Development Agreement (CRADA) for a project to improve the direct-contact condenser performance at The Geysers Power Plant. This project is the first geothermal adaptation of an advanced condenser design developed for the Ocean Thermal Energy Conversion (OTEC) systems. PG&E expects this technology to improve power plant performance and to help extend the life of the steam field by using steam more efficiently. In accordance with the CRADA, no money is transferred between the contracting parties. In this case the Department of Energy is funding NREL for their efforts in this project and PG&E is contributing funds in kind. Successful application of this technology at The Geysers will provide a basis for NREL to continue to develop this technology for other geothermal and fossil power plant systems.

  16. Geologic research at the Geysers -- 1996

    Energy Technology Data Exchange (ETDEWEB)

    Hulen, J.B.

    1997-12-31

    In response to the onset of field-wide pressure declines at The Geysers geothermal field in northern California the Department of Energy`s Geothermal Division in 1990 inaugurated sponsorship of a dedicated, multiyear research effort designed to mitigate the pressure drop and to allow steamfield operators to make more informed forecasts of steam supply and quality well into the 21st century. EGI and its predecessor, the University of Utah Research Institute, have from the onset been key participants in this important research effort. For example, utilizing fluid-inclusion and stable-isotopic methods, deciphered the field`s intricate magmatic-hydrothermal history. Hulen et al. (1991, 1992) and Hulen and Nielson (1995a) identified major textural and mineralogic differences between the productive steam reservoir and its relatively impermeable caprock.

  17. A comparison of long-term changes in seismicity at The Geysers, Salton Sea, and Coso geothermal fields

    Science.gov (United States)

    Trugman, Daniel T.; Shearer, Peter M.; Borsa, Adrian A.; Fialko, Yuri

    2016-01-01

    Geothermal energy is an important source of renewable energy, yet its production is known to induce seismicity. Here we analyze seismicity at the three largest geothermal fields in California: The Geysers, Salton Sea, and Coso. We focus on resolving the temporal evolution of seismicity rates, which provides important observational constraints on how geothermal fields respond to natural and anthropogenic loading. We develop an iterative, regularized inversion procedure to partition the observed seismicity rate into two components: (1) the interaction rate due to earthquake-earthquake triggering and (2) the smoothly varying background rate controlled by other time-dependent stresses, including anthropogenic forcing. We apply our methodology to compare long-term changes in seismicity to monthly records of fluid injection and withdrawal. At The Geysers, we find that the background seismicity rate is highly correlated with fluid injection, with the mean rate increasing by approximately 50% and exhibiting strong seasonal fluctuations following construction of the Santa Rosa pipeline in 2003. In contrast, at both Salton Sea and Coso, the background seismicity rate has remained relatively stable since 1990, though both experience short-term rate fluctuations that are not obviously modulated by geothermal plant operation. We also observe significant temporal variations in Gutenberg-Richter b value, earthquake magnitude distribution, and earthquake depth distribution, providing further evidence for the dynamic evolution of stresses within these fields. The differing field-wide responses to fluid injection and withdrawal may reflect differences in in situ reservoir conditions and local tectonics, suggesting that a complex interplay of natural and anthropogenic stressing controls seismicity within California's geothermal fields.

  18. Caldwell Ranch Exploration and Confirmation Project, Northwest Geysers, CA

    Energy Technology Data Exchange (ETDEWEB)

    Walters, Mark A.

    2013-04-25

    The purpose of the Caldwell Ranch Exploration and Confirmation Project was to drill, test, and confirm the present economic viability of the undeveloped geothermal reservoir in the 870 acre Caldwell Ranch area of the Northwest Geysers that included the CCPA No.1 steam field. All of the drilling, logging, and sampling challenges were met. Three abandoned wells, Prati 5, Prati 14 and Prati 38 were re-opened and recompleted to nominal depths of 10,000 feet in 2010. Two of the wells required sidetracking. The flow tests indicated Prati 5 Sidetrack 1 (P-5 St1), Prati 14 (P-14) and Prati 38 Sidetrack 2 (P-38 St2) were collectively capable of initially producing an equivalent of 12 megawatts (MWe) of steam using a conversion rate of 19,000 pounds of steam/hour

  19. Temporal changes of static stress drop as a proxy for poroelastic effects at The Geysers geothermal field, California

    Science.gov (United States)

    Staszek, Monika; Orlecka-Sikora, Beata; Lasocki, Stanislaw; Kwiatek, Grzegorz; Leptokaropoulos, Konstantinos; Martinez-Garzon, Patricia

    2017-04-01

    One of the major environmental impacts of shale gas exploitation is triggered and induced seismicity. Due to the similarity of fluid injection process data from geothermal fields can be used as a proxy for shale gas exploitation associated seismicity. Therefore, in this paper we utilize 'The Geysers' dataset compiled within SHale gas Exploration and Exploitation induced Risks (SHEER) project. The dependence of earthquake static stress drops on pore pressure in the medium was previously suggested by Goertz-Allmann et al. (2011), who observed an increase of the static stress drop with the distance from injection well during reservoir stimulation at Deep Heat Mining project in Basel, Switzerland. Similar observation has been done by Kwiatek et al. (2014) in Berlín geothermal field, El Salvador. In this study, we use a high-quality data from The Geysers geothermal field to determine whether the static stress drops and the stress drop distributions change statistically significantly in time or not, and how such changes are correlated with the values of hypocenter depth, water injection rate, and distance from injection well. For the analyses we use a group of 354 earthquakes, which occurred in the proximity of Prati-9 and Prati-29 injection wells. Spectral parameters of these earthquakes were determined using mesh spectral ratio technique. Our results indicate that: (1) the static stress drop variation in time is statistically significant, (2) median static stress drop is inversely related to median injection rate. Therefore, it is highly expected that static stress drop is influenced by pore pressure in underground fluid injection conditions. References: Goertz-Allmann B., Goertz A., Wiemer S. (2011), Stress drop variations of induced earthquakes at the Basel geothermal site. Geophysical Research Letters, 38, L09308, doi:10.1029/2011GL047498. Kwiatek G., Bulut F., Bohnhoff M., Dresen G. (2014), High-resolution analysis of seismicity induced at Berlin geothermal field

  20. Empirical Green's tensor retrieved from ambient noise cross-correlations at The Geysers geothermal field, Northern California

    Science.gov (United States)

    Nayak, Avinash; Taira, Taka'aki; Dreger, Douglas S.; Gritto, Roland

    2018-04-01

    We retrieve empirical Green's functions in the frequency range (˜0.2-0.9 Hz) for interstation distances ranging from ˜1 to ˜30 km (˜0.22 to ˜6.5 times the wavelength) at The Geysers geothermal field, Northern California, from coherency of ambient seismic noise being recorded by a variety of sensors (broad-band, short-period surface and borehole sensors, and one accelerometer). The applied methodology preserves the intercomponent relative amplitudes of the nine-component Green's tensor that allows us to directly compare noise-derived Green's functions (NGFs) with normalized displacement waveforms of complete single-force synthetic Green's functions (SGFs) computed with various 1-D and 3-D velocity models using the frequency-wavenumber integration method and a 3-D finite-difference wave propagation method, respectively. These comparisons provide an effective means of evaluating the suitability of different velocity models to different regions of The Geysers, and assessing the quality of the sensors and the NGFs. In the T-Tangential, R-Radial, Z-Vertical reference frame, the TT, RR, RZ, ZR and ZZ components (first component: force direction, second component: response direction) of NGFs show clear surface waves and even body-wave phases for many station pairs. They are also broadly consistent in phase and intercomponent relative amplitudes with SGFs for the known local seismic velocity structure that was derived primarily from body-wave traveltime tomography, even at interstation distances less than one wavelength. We also find anomalous large amplitudes in TR, TZ, RT and ZT components of NGFs at small interstation distances (≲4 km) that can be attributed to ˜10°-30° sensor misalignments at many stations inferred from analysis of longer period teleseismic waveforms. After correcting for sensor misalignments, significant residual amplitudes in these components for some longer interstation distance (≳8 km) paths are better reproduced by the 3-D velocity

  1. Public service impacts of geothermal development: cumulative impacts study of the Geysers KGRA. Final staff report

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, K.M.

    1983-07-01

    The number of workers currently involved in the various aspects of geothermal development in the Geysers are identified. Using two different development scenarios, projections are made for the number of power plants needed to reach the electrical generation capacity of the steam resource in the Geysers. The report also projects the cumulative number of workers needed to develop the steam field and to construct, operate, and maintain these power plants. Although the number of construction workers fluctuates, most are not likely to become new, permanent residents of the KGRA counties. The administrative and public service costs of geothermal development to local jurisdications are examined, and these costs are compared to geothermal revenues accruing to the local governments. Revenues do not cover the immediate fiscal needs resulting from increases in local road maintenance and school enrollment attributable to geothermal development. Several mitigation options are discussed and a framework presented for calculating mitigation costs for school and road impacts.

  2. Preservation of the Rotorua geysers

    International Nuclear Information System (INIS)

    Allia, R.G.; Lumb, T.

    1990-01-01

    This paper reports on the preservation of the Rotorua Geysers the geothermal activity at Rotorua, New Zealand, which has always been noted for its special cultural, tourist, and scientific values. A gradual increase in the drawoff of geothermal fluid through wells since the 1950s raised national concerns in the early 1980s when spring and geyser activity significantly declined. A government-funded monitoring program began in 1982 to establish the rate and cause of the decline in activity, as well as the magnitude of the drawoff. No new wells were permitted within 1.5 km of the geyser area. By late 1985, the monitoring program confirmed that drawdown of the geothermal field was linked to the drawoff by geothermal wells. It recommended that the drawoff could be reduced by 75% by well sharing and efficiency increases. The link between well discharges and the activity of thermal decline was disputed by the Rotorua Geothermal Users Association. By late 1986, the continuing decline in field pressure was considered to be serious, so the Government recommended compulsory closure of wells within 1.5 km of the geysers, and imposed a charging policy for geothermal usage elsewhere in Rotorua. The closures were battled in the High Court, and subsequently there was also considerable local resistance and publicity to the forced entry onto private land by authorities trying to cement up wells. The combination of enforced well closures, and what was considered by some to be punitive charges for geothermal usage, resulted in an 80% reduction in geothermal well discharges by late 1989. Some of hot spring activity has returned, and geyser activity is more intense. Recently, some residents have been concerned that cooled former thermal areas near houses may be heating up again, and that the well closures have also caused a dangerous build up in gas pressure near surface. This claim is presently being investigated

  3. Characterizing Fractures in Geysers Geothermal Field by Micro-seismic Data, Using Soft Computing, Fractals, and Shear Wave Anisotropy

    Energy Technology Data Exchange (ETDEWEB)

    Aminzadeh, Fred [Univ. of Southern California, Los Angeles, CA (United States); Sammis, Charles [Univ. of Southern California, Los Angeles, CA (United States); Sahimi, Mohammad [Univ. of Southern California, Los Angeles, CA (United States); Okaya, David [Univ. of Southern California, Los Angeles, CA (United States)

    2015-04-30

    The ultimate objective of the project was to develop new methodologies to characterize the northwestern part of The Geysers geothermal reservoir (Sonoma County, California). The goal is to gain a better knowledge of the reservoir porosity, permeability, fracture size, fracture spacing, reservoir discontinuities (leaky barriers) and impermeable boundaries.

  4. Geysering in boiling channels

    Energy Technology Data Exchange (ETDEWEB)

    Aritomi, Masanori; Takemoto, Takatoshi [Tokyo Institute of Technology, Tokyo (Japan); Chiang, Jing-Hsien [Japan NUS Corp. Ltd., Toyko (Japan)] [and others

    1995-09-01

    A concept of natural circulation BWRs such as the SBWR has been proposed and seems to be promising in that the primary cooling system can be simplified. The authors have been investigating thermo-hydraulic instabilities which may appear during the start-up in natural circulation BWRs. In our previous works, geysering was investigated in parallel boiling channels for both natural and forced circulations, and its driving mechanism and the effect of system pressure on geysering occurrence were made clear. In this paper, geysering is investigated in a vertical column and a U-shaped vertical column heated in the lower parts. It is clarified from the results that the occurrence mechanism of geysering and the dependence of system pressure on geysering occurrence coincide between parallel boiling channels in circulation systems and vertical columns in non-circulation systems.

  5. Southeast Regional Wastewater Treatment Plant Facilities Improvements Project and Geysers Effluent Pipeline Project. Draft EIR/EIS: Executive summary

    International Nuclear Information System (INIS)

    1994-01-01

    The Southeast Regional Wastewater Treatment Plant (SERWTP) Facilities Improvement Plan and Geysers Effluent Pipeline and Effluent Injection Project are proposed as a plan to provide expanded wastewater treatment capabilities and to dispose of the effluent by injection in The Geysers geothermal field for purposes of power production. The project is located predominantly in the County of Lake, California, and also in part of Sonoma County. The plan includes various conventional facilities improvements in wastewater treatment to a secondary level of treatment at the SWERWTP. The plan includes facilities to convey the treated effluent in a 26-mile, 24-inch inside diameter pipeline to the Southeast Geysers. The wastewater from the SERWTP would be supplemented by raw lake water diverted from nearby Clear Lake. At The Geysers, the effluent would be directed into a system of distribution lines to wells. In the geothermal reservoir, the water will be converted to steam and collected in production wells that will direct the steam to six existing power plants. This document is a summary of a combined full Environmental Impact Report (EIR) and Environmental Impact Statement (EIS). The EIR/EIS describes the environmental impacts of the various components of the project. Mitigation measures are suggested for reducing impacts to a less than significant level

  6. Modelling of local steam condensation on walls in presence of noncondensable gases. Application to a local calculation in reactor containment using the multidimensional geyser code

    International Nuclear Information System (INIS)

    Benet, L.V.; Caroli, C.; Cornet, P.; Coulon, N.; Magnaud, J.P.

    1995-01-01

    The frame of this paper is the study of severe accidents of pressurized water reactors (PWR). The need for containment modelling, and in particular for hydrogen risk study, was reinforced in France after 1990, with the requirement of taking into account severe accidents in design of future plants. This new need of assessing the transient local hydrogen concentration incited us to develop the multidimensional code GEYSER for containment analysis. This code, developed by the Department of Mechanics and Technology of the French Atomic Energy Commission, is presented here with a detailed example of calculation. We describe the mixture, whose constituents are noncondensable gases (air or air and hydrogen) and water vapor liquid, by a compressible homogeneous diphasic model. The wall condensation is based on the Chilton-Colburn formulation and heat mass transfer analogy. We present a transient two-dimensional axisymmetric calculation of a simplified accidental sequence during one hour. The calculation in the large volume of a reactor containment consists of an injection of vapor, first important then moderate, followed by an injection of hydrogen. (authors). 8 refs., 4 figs., 4 tabs

  7. A Multi-Method Experiment to Investigate Geyser Dynamics: Lone Star Geyser, Yellowstone National Park

    Science.gov (United States)

    Hurwitz, S.; Vandemeulebrouck, J.; Johnston, M. J.; Sohn, R. A.; Karlstrom, L.; Rudolph, M. L.; Murphy, F.; McPhee, D. K.; Glen, J. M.; Soule, S. A.; Pontbriand, C.; Meertens, C. M.

    2011-12-01

    Geysers are intermittently discharging hot springs that are driven by steam and non-condensable gas. They provide unique opportunities to study multiphase eruption processes and the geophysical signals they induce. In September 2010 we carried out a four-day experiment at Lone Star Geyser in Yellowstone National Park. The geyser is located about 5 km SSE of Old Faithful Geyser and 75 m north of the Upper Firehole River. Lone Star is a cone geyser that was selected for the experiment because it is isolated from other geysers, its eruptions are vigorous and voluminous, and its eruption intervals are relatively constant and predictable, occurring approximately every 3 hours. We made measurements during 32 eruption cycles using a suite of instruments including a broadband seismometer, 2 microphones, 5 platform tiltmeters, 3 collimating InfraRed sensors, 2 gravimeters, 2 self-potential sensors, 2 Light Detection And Ranging (LiDAR) scanners, a Forward Looking InfraRed (FLIR) camera, high-speed video cameras, and stream gauging. We also integrated meteorological data from nearby weather stations. The large dataset acquired during the experiment allows for the detection of a myriad of processes in the subsurface and in the erupting column at many different frequencies. The analyzed data yield new insights on multiphase eruptive processes that have implications for understanding self-organized, intermittent processes in nature that result from phase separation and localized input of energy and mass. The geophysical signals recorded during the experiment allow comparison with signals recorded in more complex volcanic systems where gas-driven and magma-driven processes are often hard to distinguish.

  8. Southeast Regional Wastewater Treatment Plant Facilities Improvements Project and Geysers Effluent Pipeline Project. Draft EIR/EIS, Volume 2 of 2: Appendices

    International Nuclear Information System (INIS)

    1994-01-01

    The Southeast Regional Wastewater Treatment Plant (SERWTP) Facilities Improvement Plan and Geysers Effluent Pipeline and Effluent Injection Project are proposed as a plan to provide expanded wastewater treatment capabilities and to dispose of the effluent by injection in The Geysers geothermal field for purposes of power production. The project is located predominantly in the County of Lake, California, and also in part of Sonoma County. The plan includes various conventional facilities improvements in wastewater treatment to a secondary level of treatment at the SWERWTP. The plan includes facilities to convey the treated effluent in a 26-mile, 24-inch inside diameter pipeline to the Southeast Geysers. The wastewater from the SERWTP would be supplemented by raw lake water diverted from nearby Clear Lake. At The Geysers, the effluent would be directed into a system of distribution lines to wells. In the geothermal reservoir, the water will be converted to steam and collected in production wells that will direct the steam to six existing power plants. This document is a summary of a combined full Environmental Impact Report (EIR) and Environmental Impact Statement (EIS). The EIR/EIS describes the environmental impacts of the various components of the project. Mitigation measures are suggested for reducing impacts to a less than significant level. This report contains appendices A and B. Appendix A contains notices of preparation/notices of intent and EIR/EIS scoping comments. Appendix B contains GeothermEx, Inc., analysis of Geothermal Reservoir Effects and Induced Seismicity

  9. The Geysers-Clear Lake geothermal area, California - an updated geophysical perspective of heat sources

    Science.gov (United States)

    Stanley, W.D.; Blakely, R.J.

    1995-01-01

    The Geysers-Clear Lake geothermal area encompasses a large dry-steam production area in The Geysers field and a documented high-temperature, high-pressure, water-dominated system in the area largely south of Clear Lake, which has not been developed. An updated view is presented of the geological/geophysical complexities of the crust in this region in order to address key unanswered questions about the heat source and tectonics. Forward modeling, multidimensional inversions, and ideal body analysis of the gravity data, new electromagnetic sounding models, and arguments made from other geophysical data sets suggest that many of the geophysical anomalies have significant contributions from rock property and physical state variations in the upper 7 km and not from "magma' at greater depths. Regional tectonic and magmatic processes are analyzed to develop an updated scenario for pluton emplacement that differs substantially from earlier interpretations. In addition, a rationale is outlined for future exploration for geothermal resources in The Geysers-Clear Lake area. -from Authors

  10. Eruptions at Lone Star geyser, Yellowstone National Park, USA: 2. Constraints on subsurface dynamics

    Science.gov (United States)

    Vandemeulebrouck, Jean; Sohn, Robert A.; Rudolph, Maxwell L.; Hurwitz, Shaul; Manga, Michael; Johnston, Malcolm J.S.; Soule, S. Adam; McPhee, Darcy K.; Glen, Jonathan M.G.; Karlstrom, Leif; Murphy, Fred

    2014-01-01

    We use seismic, tilt, lidar, thermal, and gravity data from 32 consecutive eruption cycles of Lone Star geyser in Yellowstone National Park to identify key subsurface processes throughout the geyser's eruption cycle. Previously, we described measurements and analyses associated with the geyser's erupting jet dynamics. Here we show that seismicity is dominated by hydrothermal tremor (~5–40 Hz) attributed to the nucleation and/or collapse of vapor bubbles. Water discharge during eruption preplay triggers high-amplitude tremor pulses from a back azimuth aligned with the geyser cone, but during the rest of the eruption cycle it is shifted to the east-northeast. Moreover, ~4 min period ground surface displacements recur every 26 ± 8 min and are uncorrelated with the eruption cycle. Based on these observations, we conclude that (1) the dynamical behavior of the geyser is controlled by the thermo-mechanical coupling between the geyser conduit and a laterally offset reservoir periodically filled with a highly compressible two-phase mixture, (2) liquid and steam slugs periodically ascend into the shallow crust near the geyser system inducing detectable deformation, (3) eruptions occur when the pressure decrease associated with overflow from geyser conduit during preplay triggers an unstable feedback between vapor generation (cavitation) and mass discharge, and (4) flow choking at a constriction in the conduit arrests the runaway process and increases the saturated vapor pressure in the reservoir by a factor of ~10 during eruptions.

  11. Periodic changes in effluent chemistry at cold-water geyser: Crystal geyser in Utah

    Science.gov (United States)

    Han, Weon Shik; Watson, Z. T.; Kampman, Niko; Grundl, Tim; Graham, Jack P.; Keating, Elizabeth H.

    2017-07-01

    Crystal geyser is a CO2-driven cold-water geyser which was originally drilled in the late 1930's in Green River, Utah. Utilizing a suite of temporal groundwater sample datasets, in situ monitoring of temperature, pressure, pH and electrical conductivity from multiple field trips to Crystal geyser from 2007 to 2014, periodic trends in groundwater chemistry from the geyser effluent were identified. Based on chemical characteristics, the primary sourcing aquifers are characterized to be both the Entrada and Navajo Sandstones with a minor contribution from Paradox Formation brine. The single eruption cycle at Crystal geyser lasted over four days and was composed of four parts: Minor Eruption (mEP), Major Eruption (MEP), Aftershock Eruption (Ae) and Recharge (R). During the single eruption cycle, dissolved ionic species vary 0-44% even though the degree of changes for individual ions are different. Generally, Na+, K+, Cl- and SO42- regularly decrease at the onset and throughout the MEP. These species then increase in concentration during the mEP. Conversely, Ca2+, Mg2+, Fe2+ and Sr2+ increase and decrease in concentration during the MEP and mEP, respectively. The geochemical inverse modeling with PHREEQC was conducted to characterize the contribution from three end-members (Entrada Sandstone, Navajo Sandstone and Paradox Formation brine) to the resulting Crystal geyser effluent. Results of the inverse modeling showed that, during the mEP, the Navajo, Entrada and brine supplied 62-65%, 36-33% and 1-2%, respectively. During the MEP, the contribution shifted to 53-56%, 45-42% and 1-2% for the Navajo, Entrada and Paradox Formation brine, respectively. The changes in effluent characteristics further support the hypothesis by Watson et al. (2014) that the mEP and MEP are driven by different sources and mechanisms.

  12. Numerical simulation for cyclic steam injection at Santa Clara field

    International Nuclear Information System (INIS)

    Rodriguez, Edwin; Barrios, Wilson; Sandoval, Roy; Santos, Nicolas; Cortes, Ingrid

    2008-01-01

    This article presents the methodology used and the results obtained in the construction, match and prediction of the first thermal composition simulation model done in Colombia by employing advanced thermal process commercial software, globally recognized because of its effectiveness in modeling these types of processes (CMG-STARS, 2005). The Santa Clara and Palermo fields were modeled and an excellent history match was achieved. All in all 28 wells and 17 years of production were matched. Two production scenes were proposed. The first involved primary production from existing wells, in other words: primary production; and a second scene where all the wells in the field are converted into injectors and producers, to simulate cyclic steam injection. This injection process included a series of sensitivity studies for several of the parameters involved in this technology, such as: pressure and temperature injection, time and rate of injection, heat injected, soaking period, steam quality, and injection cycles. This sensitivity study was focused on optimizing the processes to obtain the maximum end recovery possible. The information entered into the simulator was validated by laboratory tests developed at the Instituto Colombiano del Petroleo (ICP). Among the tests performed the following were assessed: rock compressibility, relative permeability curve behavior at different temperatures, formation sensitivity to injection fluids, DRX analysis and residual saturation of crude oil for steam injection. The aforementioned results are documented in this paper

  13. Oxygen isotope geochemistry of The Geysers reservoir rocks, California

    Energy Technology Data Exchange (ETDEWEB)

    Gunderson, Richard P.; Moore, Joseph N.

    1994-01-20

    Whole-rock oxygen isotopic compositions of Late Mesozoic graywacke, the dominant host rock at The Geysers, record evidence of a large liquid-dominated hydrothermal system that extended beyond the limits of the present steam reservoir. The graywackes show vertical and lateral isotopic variations that resulted from gradients in temperature, permeability, and fluid composition during this early liquid-dominated system. All of these effects are interpreted to have resulted from the emplacement of the granitic "felsite" intrusion 1-2 million years ago. The {delta}{sup 18}O values of the graywacke are strongly zoned around a northwest-southeast trending low located near the center of and similar in shape to the present steam system. Vertical isotopic gradients show a close relationship to the felsite intrusion. The {delta}{sup 18}O values of the graywacke decrease from approximately 15 per mil near the surface to 4-7 per mil 300 to 600 m above the intrusive contact. The {delta}{sup 18}O values then increase downward to 8-10 per mil at the felsite contact, thereafter remaining nearly constant within the intrusion itself. The large downward decrease in {delta}{sup 18}O values are interpreted to be controlled by variations in temperature during the intrusive event, ranging from 150{degree}C near the surface to about 425{degree}C near the intrusive contact. The upswing in {delta}{sup 18}O values near the intrusive contact appears to have been caused by lower rock permeability and/or heavier fluid isotopic composition there. Lateral variations in the isotopic distributions suggests that the effects of temperature were further modified by variations in rock permeability and/or fluid-isotopic composition. Time-integrated water:rock ratios are thought to have been highest within the central isotopic low where the greatest isotopic depletions are observed. We suggest that this region of the field was an area of high permeability within the main upflow zone of the liquid

  14. Two-phase flow field simulation of horizontal steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Rabiee, Ataollah; Kamalinia, Amir Hossein; Hadad, Kamal [School of Mechanical Engineering, Shiraz University, Shiraz (Iran, Islamic Republic of)

    2017-02-15

    The analysis of steam generators as an interface between primary and secondary circuits in light water nuclear power plants is crucial in terms of safety and design issues. VVER-1000 nuclear power plants use horizontal steam generators which demand a detailed thermal hydraulics investigation in order to predict their behavior during normal and transient operational conditions. Two phase flow field simulation on adjacent tube bundles is important in obtaining logical numerical results. However, the complexity of the tube bundles, due to geometry and arrangement, makes it complicated. Employment of porous media is suggested to simplify numerical modeling. This study presents the use of porous media to simulate the tube bundles within a general-purpose computational fluid dynamics code. Solved governing equations are generalized phase continuity, momentum, and energy equations. Boundary conditions, as one of the main challenges in this numerical analysis, are optimized. The model has been verified and tuned by simple two-dimensional geometry. It is shown that the obtained vapor volume fraction near the cold and hot collectors predict the experimental results more accurately than in previous studies.

  15. How Do Modern Extreme Hydrothermal Environments Inform the Identification of Martian Habitability? The Case of the El Tatio Geyser Field

    Directory of Open Access Journals (Sweden)

    Roberto Barbieri

    2014-11-01

    Full Text Available Despite the success in knowledge gained by the Mars missions in the last two decades, the search for traces of life on Mars is still in progress. The reconstruction of (paleo- environments on Mars have seen a dramatic increase, in particular with regard to the potentially habitable conditions, and it is now possible to recognize a significant role to subaerial hydrothermal processes. For this reason, and because the conditions of the primordial Earth—when these extreme environments had to be common—probably resembled Mars during its most suitable time to host life, research on terrestrial extreme hydrothermal habitats may assist in understanding how to recognize life on Mars. A number of geological and environmental reasons, and logistics opportunities, make the geothermal field of El Tatio, in the Chilean Andes an ideal location to study.

  16. Life cycle of a geyser discharge apron: Evidence from Waikite Geyser, Whakarewarewa geothermal area, North Island, New Zealand

    Science.gov (United States)

    Jones, Brian; Renaut, Robin W.; Owen, R. Bernhart

    2011-05-01

    Waikite, a geyser located in the Whakarewarewa geothermal area on the North Island, New Zealand, has a history of eruptive-dormancy cycles that have been attributed to natural and anthropogenic causes. The last cycle involved an active period from ~ 1932 to 1968/69 that was followed by a period of dormancy that continues today. Such cycles are important because they control the temporal development of the discharge apron. When the geyser is active, growth of the discharge apron is dictated by the precipitation of opal-A, which is controlled by factors such as discharge patterns, water chemistry, pH, temperature, rate of cooling, and the resident microbiota. With dormancy, conditions change radically because water no longer flows down the discharge apron. Instead, the discharge apron lapses into a phase of degradation that, on Waikite, is evident from (1) deflation of the apron surface, (2) blocks splaying off the apron margins along margin-parallel fractures, (3) tension fractures, (4) saucer-shaped collapse zones, (5) increasingly unstable surfaces resulting from subsurface opal-A dissolution, (6) fractures, from which steam and other gases emanate, and (7) incursion of native vegetation around the edge of the apron and on the distal parts of the discharge apron. When the geyser becomes active again, silica precipitation will resume and the discharge apron will once again accrete vertically and expand laterally. Analysis of the Waikite system shows that successions that develop on geyser discharge aprons are formed of unconformity-bounded packages of sinter that reflect the eruptive-dormancy history of the parent geyser.

  17. Effects of geothermal energy utilization on stream biota and water quality at The Geysers, California. Final report. [Big Sulphur, Little Sulphur, Squaw, and Pieta Creeks

    Energy Technology Data Exchange (ETDEWEB)

    LeGore, R.S.

    1975-01-01

    The discussion is presented under the following section headings: biological studies, including fish, insects, and microbiology; stream hydrology; stream water quality, including methods and results; the contribution of tributaries to Big Sulphur Creek, including methods, results, and tributary characterization; standing water at wellheads; steam condensate quality; accidental discharges; trout spawning bed quality; major conclusions; list of references; and appendices. It is concluded that present operational practices at Geysers geothermal field do not harm the biological resources in adjacent streams. The only effects of geothermal development observed during the study were related to operational accidents. (JGB)

  18. Simulation studies of steam-propane injection for the Hamaca heavy oil field

    Energy Technology Data Exchange (ETDEWEB)

    Venturini, G.J.; Mamora, D.D. [Texas A and M Univ., Austin, TX (United States)

    2003-07-01

    Laboratory experiments have been conducted at Texas A and M University to examine the use of steam additives such as propane, methane and nitrogen to improve the production of heavy oils and increase steam recovery efficiency. In particular, the use of steam-propane injection for heavy Hamaca crude oil with API gravity of 9.3 and viscosity of 25,000 cp at 50 degrees C was examined. Experimental runs involved the injection of steam or propane into injection cells at a constant rate, temperature and cell outlet pressure. The experimental results suggest that the use of steam-propane injection may translate to reduction of fuel costs for field injections. Initially, propane-steam injection resulted in a two-month oil production acceleration compared to pure steam injection. A significant gain in discounted revenue and savings in steam injection costs could be realized. The study also showed the oil product rate peak with steam-propane injection was much higher than that with pure steam injection. The oil production acceleration increases with increasing propane content. Oil recovery at the end of a five-year forecast period increases by 6.7 per cent of original oil in place (OOIP) compared to 2.3 per cent OOIP with pure steam injection. 12 refs., 6 tabs., 28 figs.

  19. "Tepid" Geysers above salt caverns

    Science.gov (United States)

    Bérest, Pierre; Brouard, Benoît; Zakharov, Vassily

    2018-06-01

    The formation of a brine geyser erupting from the wellhead of a large underground salt cavern is described. In most cases, the brine outflow from an opened cavern is slow; it results from the cavern creep closure and the thermal expansion of the cavern brine. These two processes are smooth; however, the brine outflow often is bumpy, as it is modulated by atmospheric pressure variations that generate an elastic increase (or decrease) of both cavern and brine volumes. In addition, when the flow is fast enough, the brine thermodynamic behavior in the wellbore is adiabatic. The cold brine expelled from the cavern wellhead is substituted with warm brine entering the borehole bottom, resulting in a lighter brine column. The brine outflow increases. In some cases, the flow becomes so fast that inertia terms must be taken into account. A geyser forms, coming to an end when the pressure in the cavern has dropped sufficiently. A better picture is obtained when head losses are considered. A closed-form solution can be reached. This proves that two cases must be distinguished, depending on whether the cold brine initially contained in the wellbore is expelled fully or not. It can also be shown that geyser formation is a rare event, as it requires both that the wellbore be narrow and that the cavern be very compressible. This study stemmed from an actual example in which a geyser was observed. However, scarce information is available, making any definite interpretation difficult. xml:lang="fr"

  20. The Impact of Injection on Seismicity at The Geyses, California Geothermal Field

    OpenAIRE

    Majer, Ernest L.; Peterson, John E.

    2008-01-01

    Water injection into geothermal systems has often become a required strategy to extended and sustain production of geothermal resources. To reduce a trend of declining pressures and increasing non-condensable gas concentrations in steam produced from The Geysers, operators have been injecting steam condensate, local rain and stream waters, and most recently treated wastewater piped to the field from neighboring communities. If geothermal energy is to provide a significant increase in ene...

  1. Mechanics of Old Faithful Geyser, Calistoga, CA

    Science.gov (United States)

    Rudolph, M.L.; Manga, M.; Hurwitz, Shaul; Johnston, Malcolm J.; Karlstrom, L.; Wang, Chun-Yong

    2012-01-01

    In order to probe the subsurface dynamics associated with geyser eruptions, we measured ground deformation at Old Faithful Geyser of Calistoga, CA. We present a physical model in which recharge during the period preceding an eruption is driven by pressure differences relative to the aquifer supplying the geyser. The model predicts that pressure and ground deformation are characterized by an exponential function of time, consistent with our observations. The geyser's conduit is connected to a reservoir at a depth of at least 42 m, and pressure changes in the reservoir can produce the observed ground deformations through either a poroelastic or elastic mechanical model.

  2. Modeling of local steam condensation on walls in presence of non-condensable gases. Application to a loca calculation in reactor containment using the multidimensional geyser/tonus code

    Energy Technology Data Exchange (ETDEWEB)

    Benet, L.V.; Caroli, C.; Cornet, P. [Commissariat a l`Energie Atomique, Gif sur Yvette (France)] [and others

    1995-09-01

    This paper reports part of a study of possible severe pressurized water reactor (PWR) accidents. The need for containment modeling, and in particular for a hydrogen risk study, was reinforced in France after 1990, with the requirement that severe accidents must be taken into account in the design of future plants. This new need of assessing the transient local hydrogen concentration led to the development, in the Mechanical Engineering and Technology Department of the French Atomic Energy Commission (CEA/DMT), of the multidimensional code GEYSER/TONUS for containment analysis. A detailed example of the use of this code is presented. The mixture consisted of noncondensable gases (air or air plus hydrogen) and water vapor and liquid water. This is described by a compressible homogeneous two-phase flow model and wall condensation is based on the Chilton-Colburn formula and the analogy between heat and mass transfer. Results are given for a transient two-dimensional axially-symmetric computation for the first hour of a simplified accident sequence. In this there was an initial injection of a large amount of water vapor followed by a smaller amount and by hydrogen injection.

  3. A fast response miniature probe for wet steam flow field measurements

    International Nuclear Information System (INIS)

    Bosdas, Ilias; Mansour, Michel; Abhari, Reza S; Kalfas, Anestis I

    2016-01-01

    Modern steam turbines require operational flexibility due to renewable energies’ increasing share of the electrical grid. Additionally, the continuous increase in energy demand necessitates efficient design of the steam turbines as well as power output augmentation. The long turbine rotor blades at the machines’ last stages are prone to mechanical vibrations and as a consequence time-resolved experimental data under wet steam conditions are essential for the development of large-scale low-pressure steam turbines. This paper presents a novel fast response miniature heated probe for unsteady wet steam flow field measurements. The probe has a tip diameter of 2.5 mm, and a miniature heater cartridge ensures uncontaminated pressure taps from condensed water. The probe is capable of providing the unsteady flow angles, total and static pressure as well as the flow Mach number. The operating principle and calibration procedure are described in the current work and a detailed uncertainty analysis demonstrates the capability of the new probe to perform accurate flow field measurements under wet steam conditions. In order to exclude any data possibly corrupted by droplets’ impact or evaporation from the heating process, a filtering algorithm was developed and implemented in the post-processing phase of the measured data. In the last part of this paper the probe is used in an experimental steam turbine test facility and measurements are conducted at the inlet and exit of the last stage with an average wetness mass fraction of 8.0%. (paper)

  4. Enceladus' 101 Geysers: Phantoms? Hardly

    Science.gov (United States)

    Porco, C.; Nimmo, F.; DiNino, D.

    2015-12-01

    The discovery by the Cassini mission of present-day geysering activity capping the southern hemisphere of Saturn's moon Enceladus (eg, Porco, C. C. et al. Science 311, 1393, 2006) and sourced within a subsurface body of liquid water (eg, Postberg, F. et al. Nature 459, 1098, 2009; Porco, C.C. et al. AJ 148, 45, 2014, hereafter PEA], laced with organic compounds (eg, Waite, J.H. et al. Science 311, 1419, 2006), has been a significant one, with far-reaching astrobiological implications. In an extensive Cassini imaging survey of the moon's south polar terrain (SPT), PEA identified 101 distinct, narrow jets of small icy particles erupting, with varying strengths, from the four major fractures crossing the SPT. A sufficient spread in stereo angles of the 107 images used in that work allowed (in some cases, many) pair-wise triangulations to be computed; precise surface locations were derived for 98 jets. Recently, it has been claimed (Spitale, J.N. et al. Nature 521, 57, 2015) that the majority of the geysers are not true discrete jets, but are "phantoms" that appear in shallow-angle views of a dense continuous curtain of material with acute bends in it. These authors also concluded that the majority of the eruptive material is not in the form of jets but in the form of fissure-style 'curtain' eruptions. We argue below the contrary, that because almost all the moon's geysers were identified by PEA using multiple images with favorable viewing geometries, the vast majority of them, and likely all, are discrete jets. Specifically, out of 98 jets, no fewer than 90 to 95 were identified with viewing geometries that preclude the appearance of phantoms. How the erupting solids (i.e., icy particles) that are seen in Cassini images are partitioned between jets and inter-jet curtains is still an open question.

  5. Eruptions at Lone Star Geyser, Yellowstone National Park, USA, part 1: energetics and eruption dynamics

    Science.gov (United States)

    Karlstrom, Leif; Hurwitz, Shaul; Sohn, Robert; Vandemeulebrouck, Jean; Murphy, Fred; Rudolph, Maxwell L.; Johnston, Malcolm J.S.; Manga, Michael; McCleskey, R. Blaine

    2013-01-01

    Geysers provide a natural laboratory to study multiphase eruptive processes. We present results from a four–day experiment at Lone Star Geyser in Yellowstone National Park, USA. We simultaneously measured water discharge, acoustic emissions, infraredintensity, and visible and infrared video to quantify the energetics and dynamics of eruptions, occurring approximately every three hours. We define four phases in the eruption cycle: 1) a 28 ± 3 minute phase with liquid and steam fountaining, with maximum jet velocities of 16–28 m s− 1, steam mass fraction of less than ∼ 0.01. Intermittently choked flow and flow oscillations with periods increasing from 20 to 40 s are coincident with a decrease in jet velocity and an increase of steam fraction; 2) a 26 ± 8 minute post–eruption relaxation phase with no discharge from the vent, infrared (IR) and acoustic power oscillations gliding between 30 and 40 s; 3) a 59 ± 13 minute recharge period during which the geyser is quiescent and progressively refills, and 4) a 69 ± 14 minute pre–play period characterized by a series of 5–10 minute–long pulses of steam, small volumes of liquid water discharge and 50–70 s flow oscillations. The erupted waters ascend froma 160 − 170° C reservoir and the volume discharged during the entire eruptive cycle is 20.8 ± 4.1 m3. Assuming isentropic expansion, we calculate a heat output from the geyser of 1.4–1.5 MW, which is < 0.1% of the total heat output from Yellowstone Caldera.

  6. Visualizing intramyocardial steam formation with a radiofrequency ablation catheter incorporating near-field ultrasound.

    Science.gov (United States)

    Wright, Matthew; Harks, Erik; Deladi, Szabolcs; Fokkenrood, Steven; Zuo, Fei; Van Dusschoten, Anneke; Kolen, Alexander F; Belt, Harm; Sacher, Frederic; Hocini, Mélèze; Haïssaguerre, Michel; Jaïs, Pierre

    2013-12-01

    Steam pops are a risk of irrigated RF ablation even when limiting power delivery. There is currently no way to predict gas formation during ablation. It would be useful to visualize intramyocardial gas formation prior to a steam pop occurring using near-field ultrasound integrated into a RF ablation catheter. In an in vivo open-chest ovine model (n = 9), 86 lesions were delivered to the epicardial surface of the ventricles. Energy was delivered for 15-60 seconds, to achieve lesions with and without steam pops, based on modeling data. The ultrasound image was compared to a digital audio recording from within the pericardium by a blinded observer. Of 86 lesions, 28 resulted in an audible steam pop. For lesions that resulted in a steam pop compared to those that did not (n = 58), the mean power delivered was 8.0 ± 1.8 W versus 6.7 ± 2.0 W, P = 0.006. A change in US contrast due to gas formation in the tissue occurred in all lesions that resulted in a steam pop. In 4 ablations, a similar change in US contrast was observed in the tissue and RF delivery was stopped; in these cases, no pop occurred. The mean depth of gas formation was 0.9 ± 0.8 mm, which correlated with maximal temperature predicted by modeling. Changes in US contrast occurred 7.6 ± 7.2 seconds before the impedance rise and 7.9 ± 6.2 seconds (0.1-17.0) before an audible pop. Integrated US in an RF ablation catheter is able to visualize gas formation intramyocardially several seconds prior to a steam pop occurring. This technology may help prevent complications arising from steam pops. © 2013 Wiley Periodicals, Inc.

  7. Field test results for steam oxidation of TP347H FG - growth of inner oxide

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Jianmin, Jia; Larsen, OH

    2005-01-01

    A series of field tests have been conducted with TP347H FG in test superheater loops in coal-fired and biomass fired boilers of steam pressure 256 and 91 bar respectively. The exposure times are from 3,500 to 30,000 hours and the temperature range is from 450-630¢XC. The morphology, composition...

  8. Geophysical studies of the Crump Geyser known geothermal resource area, Oregon, in 1975

    Science.gov (United States)

    Plouff, Donald

    2006-01-01

    The U.S. Geological Survey (USGS) conducted geophysical studies in support of the resource appraisal of the Crump Geyser Known Geothermal Resource Area (KGRA). This area was designated as a KGRA by the USGS, and this designation became effective on December 24, 1970. The land classification standards for a KGRA were established by the Geothermal Steam Act of 1970 (Public Law 91-581). Federal lands so classified required competitive leasing for the development of geothermal resources. The author presented an administrative report of USGS geophysical studies entitled 'Geophysical background of the Crump Geyser area, Oregon, KGRA' to a USGS resource committee on June 17, 1975. This report, which essentially was a description of geophysical data and a preliminary interpretation without discussion of resource appraisal, is in Appendix 1. Reduction of sheets or plates in the original administrative report to page-size figures, which are listed and appended to the back of the text in Appendix 1, did not seem to significantly degrade legibility. Bold print in the text indicates where minor changes were made. A colored page-size index and tectonic map, which also show regional geology not shown in figure 2, was substituted for original figure 1. Detailed descriptions for the geologic units referenced in the text and shown on figures 1 and 2 were separately defined by Walker and Repenning (1965) and presumably were discussed in other reports to the committee. Heavy dashed lines on figures 1 and 2 indicate the approximate KGRA boundary. One of the principal results of the geophysical studies was to obtain a gravity map (Appendix 1, fig. 10; Plouff, and Conradi, 1975, pl. 9), which reflects the fault-bounded steepness of the west edge of sediments and locates the maximum thickness of valley sediments at about 10 kilometers south of Crump Geyser. Based on the indicated regional-gravity profile and density-contrast assumptions for the two-dimensional profile, the maximum

  9. Modeling and field studies of fouling in once-through steam generators

    International Nuclear Information System (INIS)

    Thompson, R.; Gaudreau, T.

    1995-01-01

    Efforts of the past 10 years to minimize fouling of the Crystal River-3 once-through steam generators are reviewed. The major focus has been on improving at-temperature pH control in the secondary cycle. Various concentrations of different pH control agents were tested in the field for hundreds of days to determine their effect on steam generator fouling. High concentrations of morpholine (50--100 ppm) in the feedwater were found to apparently produce de-fouling of the steam generators without an associated decrease in feedwater iron concentration as compared to that at lower levels of morpholine. Computer modeling of the pH(t) within the OTSG for the various chemistries tested indicates that the pH can change significantly with elevation within the steam generator by varying the pH control agent or its concentration. It is postulated that these variations in pH may change the surface charge of the tubes, tube support plates, and/or corrosion product particles in solution, to favor either deposition or repulsion of the particles, and thereby producing conditions that either favor fouling or de-fouling of the OTSG. Crystal River-3 experience indicates that corrosion product deposition and release processes inside the steam generator can be chemically manipulated to favor release, and thereby maximize plant performance, and delay or avoid costly hydraulic or chemical cleanings

  10. Santa Rosa Geysers Recharge Project: GEO-98-001. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Brauner, Edwin Jr.; Carlson, Daniel C.

    2002-10-01

    The Geysers steamfields in northern Sonoma County have produced reliable ''green'' power for many years. An impediment to long-term continued production has been the ability to provide a reliable source of injection water to replace water extracted and lost in the form of steam. The steamfield operators have historcially used cooling towers to recycle a small portion of the steam and have collected water during the winter months using stream extraction. These two sources, however, could not by themselves sustain the steamfield in the long term. The Lake County Reclaimed Water Project (SEGEP) was inititated in 1997 and provides another source of steamfield replenishment water. The Santa Rosa Geysers Recharge Project provides another significant step in replenishing the steamfield. In addition, the Santa Rosa Geysers Recharge Project has been built with capacity to potentially meet virtually all injection water requirements, when combined with these other sources. Figure 2.1 graphically depicts the combination of injection sources.

  11. Evaluation of the residual stress field in a steam generator end tube after hydraulic expansion

    International Nuclear Information System (INIS)

    Thiel, F.; Kang, S.; Chabrerie, J.

    1994-01-01

    This paper presents a finite element elastoplastic model of a nuclear steam generator end tube, used to evaluate the residual stress field existing after hydraulic expansion of the tube into the tubesheet of the heat exchanger. This model has been tested against an experimental hydraulic expansion, carried out on full scale end tubes. The operation was monitored thanks to strain gages localized on the outer surface of the tubes, subjected to elastoplastic deformations. After a presentation of the expansion test and the description of the numerical model, the authors compare the stress fields issues from the gages and from the model. The comparison shows a good agreement. These results allow them to calculate the stress field resulting from normal operating conditions, while taking into account a correct initial state of stress. Therefore the authors can improve the understanding of the behavior of a steam generator end tube, with respect to stress corrosion cracking and crack growth

  12. Droplet rotation model apply in steam uniform flow and gravitational field

    International Nuclear Information System (INIS)

    Zhang Jinyi; Bo Hanliang; Sun Yuliang; Wang Dazhong

    2012-01-01

    The mechanism droplet movement behavior and the qualitative description of droplet trajectory in the steam uniform flow field in the gravitational field were researched with droplet rotation model. According to the mechanism of gravitational field and uniform flow fields, the effects on droplets movement were analyzed and the importance of lift forces was also discussed. Finally, a general trajectory and mechanism of the droplets movement was derived which lays the groundwork for the qualitative analysis of the single-drop model and could be general enough to be used in many applications. (authors)

  13. Combustion of hydrogen/air/steam mixtures in a repeated obstacle field

    International Nuclear Information System (INIS)

    Kumar, R.K.; Bowles, E.M.; Koroll, G.W.

    1994-01-01

    Combustion experiments with hydrogen/air/steam mixtures were performed in a cylindrical vessel of 1.5-m internal diameter and 5.7-m height in a repeated obstacle field. The investigations included hydrogen concentrations in the range of 10 to 20% and steam concentrations of up to 30%. For the mixtures investigated, the flame accelerated very rapidly in the vessel, reached a peak value, and decelerated equally rapidly For hydrogen/air mixtures with hydrogen concentrations above 15%, the flame speeds reached values well in excess of the sonic velocity in the mixture. Addition of steam reduced the flame speed and the peak pressure, however, the reduction was significant only for steam concentrations >20%. Experiments performed with different obstacle spacings and flow blockages indicated that flame speed decreased with increased spacing and increased with increased blockage. The effect of initial pressure on flame speed was found to be small. For a given mixture, the peak flame speed was found to be independent of the igniter location. Simple empirical correlations have been proposed to calculate the flame speeds and peak pressures in a closed vessel with closely spaces repeated obstacles. (author)

  14. The floating desalination complex GEYSER-1

    International Nuclear Information System (INIS)

    Vorobyov, V.M.

    1997-01-01

    A conventional floating desalination complex, GEYSER-1, is presented which is capable of producing 40,000 cubic meters per day (m 3 /d) of fresh water from brackish water or seawater. The complex includes a water intake system, a preliminary water preparation system, a high-pressure pump house and a power installation based on diesel or a gas turbines with service equipment. GEYSER-1 can be transported to the place of operation either by a heavy lift ship or by towing. (author)

  15. Direct Measurement of the Volume of Liquid Water Emitted During Eruptions of Lone Star Geyser, Yellowstone National Park, Wyoming

    Science.gov (United States)

    Murphy, F.; Hurwitz, S.; Johnston, M. J.; Vandemeulebrouck, J.; Pontbriand, C.; Sohn, R. A.; Karlstrom, L.; Rudolph, M. L.

    2011-12-01

    In September, 2010 a comprehensive series of instrumental observations was carried out at Lone Star Geyser in Yellowstone National Park to measure changes in the geyser and its surroundings during eruptions. That project included measurements of flow in the streams that drain the geyser area. Three small streams convey liquid water from the geyser and many of the surrounding hot springs to the Firehole River, about 75 m south of the geyser cone. We developed rating curves for two of these streams by measuring channel cross-sections and timing floating markers (using stopwatches and video recordings) while simultaneously recording stream depth at two-second intervals at two locations using pressure transducers and dataloggers. We estimated the flow in the third (ungaged) stream to be 0.15 of the flow in the easternmost stream, with which it shares a source area and part of its channel. The eruption cycle takes about 3 hours, and a total of nine eruption cycles were observed. During these 3-hour cycles the geyser and the nearby hot springs deliver a total of between 15 and 28 m3 of water to the Firehole River. During the 10-20 minutes of the main phase of an eruption, the geyser delivered between 8 and 11 m3 of water to the three streams. The volume of water emitted during eruptions appears to display a significant diurnal variation which strongly correlates with air temperature, with significantly more flow during early afternoon hours. There were also significant variations in the distribution of flow between the different channels. Our calculations suggest that losses due to evaporation along the flow channels are negligible, and losses due to infiltration appear to be small. The calculated volumes of water discharge do not account for the volume of erupted steam or evaporation of liquid water from the jet. Steam discharge will be assessed using image analysis of high speed video. The calculated volumes provide accurate and important constraint for models of

  16. Cumulative biological impacts of The Geysers geothermal development

    Energy Technology Data Exchange (ETDEWEB)

    Brownell, J.A.

    1981-10-01

    The cumulative nature of current and potential future biological impacts from full geothermal development in the steam-dominated portion of The Geysers-Calistoga KGRA are identified by the California Energy Commission staff. Vegetation, wildlife, and aquatic resources information have been reviewed and evaluated. Impacts and their significance are discussed and staff recommendations presented. Development of 3000 MW of electrical energy will result in direct vegetation losses of 2790 acres, based on an estimate of 11.5% loss per lease-hold of 0.93 acres/MW. If unmitigated, losses will be greater. Indirect vegetation losses and damage occur from steam emissions which contain elements (particularly boron) toxic to vegetation. Other potential impacts include chronic low-level boron exposure, acid rain, local climate modification, and mechanical damage. A potential exists for significant reduction and changes in wildlife from direct habitat loss and development influences. Highly erosive soils create the potential for significant reduction of aquatic resources, particularly game fish. Toxic spills have caused some temporary losses of aquatic species. Staff recommends monitoring and implementation of mitigation measures at all geothermal development stages.

  17. Hideout of sea water impurities in steam generator tube deposits: laboratory and field studies

    International Nuclear Information System (INIS)

    Balakrishnan, P.V.; Turner, C.W.; Thompson, R.; Sawochka, S.

    1996-01-01

    Sea water impurities hide out within thin (∼10 μm) deposits on steam generator tubes, as demonstrated by both laboratory studies using segments of fouled steam generator tubes pulled in 1992 from Crystal River-3 nuclear power station and field hideout return studies performed during recent plant shutdowns. Laboratory tests performed at 279 o C (534 o F) and heat fluxes ranging from 35 to 114 kW/m 2 (11,100 - 36,150 Btu/h.ft 2 ), conditions typical of the lower tubesheet to the first support plate region of a once-through steam generator, showed that impurity hideout can occur in thin free-span tube deposits. The extent of hideout increased with increasing heat flux. Soluble species, such as sodium and chloride ions, returned promptly to the bulk water from the deposits when the heat flux was turned off, whereas less soluble species, such as calcium sulfate and magnesium hydroxide, returned more slowly. Recent field hideout return studies performed at Crystal River-3 where the water level in the steam generators was maintained below the first tube support plate during the shutdown, thus wetting only the thin deposits in the free span and the small sludge pile, corroborate the laboratory findings, showing that hideout does indeed occur in the free-span regions of the tubes. These findings suggest that hideout within tube deposits has to be accounted for in the calculation of crevice chemistry from hideout return studies and in controlling the bulk chemistry using the molar ratio criterion. (author). 3 refs., 4 tabs., 3 figs

  18. Optimization of Wellhead Piping Design for Production Wells at Development of Steam-Water Geothermal Fields

    Directory of Open Access Journals (Sweden)

    A.N. Shulyupin

    2017-03-01

    Full Text Available At present, the exploitation of geothermal resources develops in a fair competition with other types of energy resources. This leads to actuality of questions which associated with the more efficient use of existing wells, because cost of their drilling is a significant share of geothermal projects. In domestic practice of development of geothermal resources the steam-water wells have greatest energy potential. One way to improve the performance of these wells is a providing of smooth change of direction of motion of steam-water mixture from the vertical, in the well, to the horizontal, in steam gathering system. Typical wellhead piping of domestic steam-water wells involves the removal of the mixture through a cross bar at a right angle. Cross bar can generate considerable pressure loss that increases the operating pressure at the mouth of the well and reduces flow rate. It seems reasonable to substitute the typical cross bar by smooth pipe bend. This reduces wellhead resistance coefficient by more than on 2. Increase of curvature radius of pipe bend reduces the pressure loss to a local resistance but increases the friction pressure loss. There is an optimal curvature radius of pipe bend for minimum pressure loss in view of a local resistance and friction in the pipe bend. Calculations have shown that the optimum value for the radius of curvature is found in the range from 1.4 to 4.5 tube internal diameters. However, for technological reasons it is recommended to choose the radius of curvature from 1.4 to 2.4 diameters. Mounting of smooth pipe bend on the wellhead can provide significant economic benefits. For Mutnovka field (Kamchatka, this effect is estimated at 17.5 million rubles in year.

  19. A calculation and measurement of the flow field in a steam condenser external to the tube nest

    International Nuclear Information System (INIS)

    Stastny, M.; Feistauer, M.

    1989-01-01

    The suggested physical and mathematical model is used to solve the flow of steam normal to the cooling tubes of condenser cross-sections in the region external to the nests. Numerical calculations are carried out by means of a multipurpose system of programmes for the finite element method and a programme for the boundary layer calculation. The results of the calculations are compared with measurements on the condenser of a 500MW steam turbine. The calculations of the flow field in a double pass condenser for the 1000MW saturated steam turbine are described. (author)

  20. Final cost reduction study for the Geysers Recharge Alternative. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-11-01

    The purpose of this study is to determine whether or not cost reduction opportunities exist for the Geysers Recharge Alternative as defined in the Santa Rosa Subregional Long-Term Wastewater Project EIR/EIS. The City of Santa Rosa has been directed to have a plan for reclaimed water disposal in place by 1999 which will meet future capacity needs under all weather conditions. A Draft EIR/EIS released in July 1996 and a Final EIR certified in June 1997 examine four primary alternatives plus the No Action Alternative. Two of the primary alternatives involve agricultural irrigation with reclaimed water, either in western or southern Sonoma County. Another involves increased discharge of reclaimed water into the Russian River. The fourth involves using reclaimed water to replenish the geothermal reservoir at the Geysers. The addition of this water source would enable the Geysers operators to produce more steam from the geothermal area and thereby prolong the life and economic production level of the steamfield and the geothermal power plants supplied by the steamfield. This study provides additional refined cost estimates for new scenarios which utilize an alternative pipeline alignment and a range of reclaimed water flows, which deliver less water to the Geysers than proposed in the EIR/EIS (by distributing flow to other project components). Also, electrical power rates were revised to reflect the recent changes in costs associated with deregulation of the power industry. In addition, this report provides information on sources of potential public and private funding available and future environmental documentation required if the cost reduction scenarios were to be selected by the City as part of their preferred alternative.

  1. Influence of sodium deposits in steam generator tubes on remote field eddy current signals

    Energy Technology Data Exchange (ETDEWEB)

    Thirunavukkarasu, S. [EMSI Section, NDE Division, Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu (India); Rao, B.P.C. [EMSI Section, NDE Division, Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu (India)], E-mail: bpcrao@igcar.gov.in; Vaidyanathan, S.; Jayakumar, T.; Raj, Baldev [EMSI Section, NDE Division, Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu (India)

    2008-04-15

    The presence of sodium deposits in defective regions of steam generator (SG) tubes of fast-breeder reactors is expected to influence the remote field eddy current (RFEC) signals. By exposing five SG tubes having uniform wall loss grooves to a sodium environment in a specially designed test vessel, changes in the shape of RFEC signals were observed and it was possible to approximate the volume of sodium deposited in defects. An invariant signal parameter was determined for quantitative characterization of defects despite the presence of sodium in the defects.

  2. The enthalpy of the heat-carrying fluids and the energy of eruption of velican geyser, Kamchatka, U.S.S.R.

    Science.gov (United States)

    Steinberg, G. S.

    1980-10-01

    The enthalphy of the heat carrying fluids liquid water or mixture of water plus steam) which feeds the biggest Kamchatka geyser, Velican is obtained from the critical quantity of heat Q critical, which is the net heat lost during the previous eruption and must be resupplied (stored) to trigger the next eruption. There are two unknowns in the heat balance equation for the geyser that cannot be determined from observations on the geyser in its natural state: critical and the enthalpy of the heat-carrying fluids Io. In order to obtain a system of two equations for unambiguous determination of these parameters, we made temporary physical changes that affected the natural interval between geyser eruptions and constructed the heat balance equations for the different regimes (i.e., natural and induced intervals). The changes in interval of Velican geyser were achieved by changing the area of its surface pool, using dams. For geysers with large surface pool areas, the heat loss from the surface (mainly through evaporation) is of the same order and sometimes larger than the losses from discharge of hot water. The change of surface pool area for Velican geyser from 12 m 2 (in natural state) to 4.5 and 36.7 m 2 in experiments leads to changes of its interval from an average of 5 hours and 35 minutes in natural state to 4 hours and 59 minutes and 8 hours and 8 minutes, respectively. From the three independent equations of heat balance we obtained three sets cf values for the enthalpy, Io and the critical energy, Q critical, which differ from each other by less than 1%: Io= 176 kcal/kg ∗, Q critical = 3.78 × 10 6 kcal. The interval between eruptions of Velican geyser tends to change linearly with vent area (within our experimental range). The range or interval values (the difference between maximal and minimal periods) also depends linearly on vent area. These two systematics are due to the facts that the increase of vent surface area causes increased heat loss by

  3. Seismic velocity structure and microearthquake source properties at The Geysers, California, geothermal area

    Energy Technology Data Exchange (ETDEWEB)

    O' Connell, D.R.

    1986-12-01

    The method of progressive hypocenter-velocity inversion has been extended to incorporate S-wave arrival time data and to estimate S-wave velocities in addition to P-wave velocities. S-wave data to progressive inversion does not completely eliminate hypocenter-velocity tradeoffs, but they are substantially reduced. Results of a P and S-wave progressive hypocenter-velocity inversion at The Geysers show that the top of the steam reservoir is clearly defined by a large decrease of V/sub p//V/sub s/ at the condensation zone-production zone contact. The depth interval of maximum steam production coincides with minimum observed V/sub p//V/sub s/, and V/sub p//V/sub s/ increses below the shallow primary production zone suggesting that reservoir rock becomes more fluid saturated. The moment tensor inversion method was applied to three microearthquakes at The Geysers. Estimated principal stress orientations were comparable to those estimated using P-wave firstmotions as constraints. Well constrained principal stress orientations were obtained for one event for which the 17 P-first motions could not distinguish between normal-slip and strike-slip mechanisms. The moment tensor estimates of principal stress orientations were obtained using far fewer stations than required for first-motion focal mechanism solutions. The three focal mechanisms obtained here support the hypothesis that focal mechanisms are a function of depth at The Geysers. Progressive inversion as developed here and the moment tensor inversion method provide a complete approach for determining earthquake locations, P and S-wave velocity structure, and earthquake source mechanisms.

  4. VACUUM STEAMING PROCESSES APPLIED TO YARNS, ITS APPLICATION FIELDS AND IMPROVEMENTS

    Directory of Open Access Journals (Sweden)

    Özcan ÖZDEMİR

    2005-02-01

    Full Text Available The new techniques used today focus mainly on increases in production speed. For this reason yarns to be used in high speed machines is required to be of high quality. On the other hand high speed frequently causes the degree of yarn moisture to fall minimum level. This decreases in the degree of yarn moisture have negative effects on yarn strength. Since better moisture level increases the yarn strength, yarn is worked more efficiently in weaving and knitting. However each production step in textile plants causes tension in yarn and fibre. Yarns tend to snarl in order to relax themselves.Tension and snarling may lead to problems in the following proceses, thus decreasing productivity. Therefore, the moisture content of yarns should be increased and their tension should be eleminated. In this article we have studied vacuum steaming widely used to remedy above mentioned yarn problems, its application fields and new improvements in this field.

  5. Impact of water hardness on energy consumption of geyser heating ...

    African Journals Online (AJOL)

    Therefore, the Eskom Research, Testing, and Development Business Unit embarked on a study to examine total water hardness as a chemical parameter that may impact the power consumption of electrical geyser heating elements. An accelerated scaling method was developed to lime-scale the geyser heating elements ...

  6. Steam generator waterlancing at Darlington NGS (system development and field application)

    International Nuclear Information System (INIS)

    Seppala, D.; Malaugh, J.; Kiisel, E.; Kamler, F.

    1996-01-01

    From the initial steam generator (SG) inspections at Darlington Nuclear Generating Station (DNGS), the authors know that the sludge accumulations on the secondary side tubesheets have been minimal. DNGS is a fairly new station but the experience at the older Ontario Hydro plants have shown that significant accumulations will happen. A pro-active strategy has been adopted for maintaining SGs that will minimize corrosion product accumulation and the potential for component degradation. During the four year planned Unit maintenance outages, SGs will be inspected and waterlanced using a waterlance system designed and built by Babcock and Wilcox International. This automated state-of-the-art system also allows fully recorded inspections of the tubesheet/first half-lattice supports. Some of the key elements covered include results of the initial field application (May, 1995), system development and design, system qualification, cleaning performance, and lessons learned for future outages

  7. Resource, technology, and environment at the geysers

    Energy Technology Data Exchange (ETDEWEB)

    Weres, O.; Tsao, K.; Wood, B.

    1977-06-01

    A general review, description, and history of geothermal development at the Geysers is presented. Particular emphasis is placed on environmental impacts of development of the area. The discussion is presented under the following chapter titles: introduction; energy, enthalpy and the First Law; vapor-producing geothermal reservoirs--review and models; geothermal; entropy and the Second Law; power plants--basics; H/sub 2/S emissions; hydrogen sulfide--possible health effects and odor; other emissions; power plant hydrogen sulfide abatement; hot water based geothermal development; phytotoxicity of geothermal emissions; appendices; and bibliography. (JGB)

  8. Remote field eddy current testing for steam generator inspection of fast reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Noriyasu, E-mail: noriyasu.kobayashi@toshiba.co.jp [Power and Industrial Systems Research and Development Center, Toshiba Corporation, 8, Shinsugita-cho, Isogo-ku, Yokohama 235-8523 (Japan); Ueno, Souichi; Nagai, Satoshi; Ochiai, Makoto [Power and Industrial Systems Research and Development Center, Toshiba Corporation, 8, Shinsugita-cho, Isogo-ku, Yokohama 235-8523 (Japan); Jimbo, Noboru [Isogo Nuclear Engineering Center, Toshiba Corporation, 8, Shinsugita-cho, Isogo-ku, Yokohama 235-8523 (Japan)

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer We confirmed defect detection performances of remote field eddy current testing. Black-Right-Pointing-Pointer It is difficult to inspect outer surface of double wall tube steam generator. Black-Right-Pointing-Pointer We used coils with flux guide made of iron-nickel alloy for high sensitivity. Black-Right-Pointing-Pointer Output voltage of detector coil increased more than 100 times. Black-Right-Pointing-Pointer We were able to detect small hole defect of 1mm in diameter on outer surface. - Abstract: We confirmed the defect detection performances of the remote field eddy current testing (RFECT) in order to inspect the helical-coil-type double wall tube steam generator (DWTSG) with the wire mesh layer for the new small fast reactor 4S (Super-Safe, Small and Simple). As the high sensitivity techniques, we tried to increase the direct magnetic field intensity in the vicinity of the inner wall of the tube and decrease the direct magnetic field around the central axis of the tube using the exciter coil with the flux guide made of the iron-nickel alloy. We adopted the horizontal type multiple detector coils with the flux guides arrayed circumferentially to enhance the sensitivity of the radial component. According to the experimental results, the output voltage of the detector coil in the region of indirect magnetic field increased more than 100 times by the application of the exciter and detector coils with the flux guides. Finally, we were able to detect the small hole defect of 1 mm in diameter and 20% of the outer tube thickness in depth over the wire mesh layer by the adoption of the exciter coil and horizontal type multiple detector coils with the flux guides. We also confirmed that the RFECT probe is useful for detecting thinning defects. These experimental results indicated that there is the possibility that we can inspect the double wall tube with the wire mesh layer using the RFECT.

  9. Temperature fields induced by direct contact condensation of steam in a cross-flow in a channel

    NARCIS (Netherlands)

    Clerx, N.; van Deurzen, L.G.M.; Pecenko, A.; Liew, R.; van der Geld, C.W.M.; Kuerten, Johannes G.M.

    2011-01-01

    The temperature fields in the center plane of a channel with a square cross-section have been measured. Steam injected at relatively low mass fluxes through a small hole in one of the walls of the channel condensed intermittently in a small area close to the inlet. The upstream temperature of the

  10. Field test of two high-pressure direct-contact downhole steam generators. Volume II. Oxygen/diesel system

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, J.B.

    1983-07-01

    A field test of an oxygen/diesel fuel, direct contact steam generator has been completed. The field test, which was a part of Project DEEP STEAM and was sponsored by the US Department of Energy, involved the thermal stimulation of a well pattern in the Tar Zone of the Wilmington Oil Field. The activity was carried out in cooperation with the City of Long Beach and the Long Beach Oil Development Company. The steam generator was operated at ground level, with the steam and combustion products delivered to the reservoir through 2022 feet of calcium-silicate insulated tubing. The objectives of the test included demonstrations of safety, operational ease, reliability and lifetime; investigations of reservoir response, environmental impact, and economics; and comparison of those points with a second generator that used air rather than oxygen. The test was extensively instrumented to provide the required data. Excluding interruptions not attributable to the oxygen/diesel system, steam was injected 78% of the time. System lifetime was limited by the combustor, which required some parts replacement every 2 to 3 weeks. For the conditions of this particular test, the use of trucked-in LOX resulted in liess expense than did the production of the equivalent amount of high pressure air using on site compressors. No statistically significant production change in the eight-acre oxygen system well pattern occurred during the test, nor were any adverse effects on the reservoir character detected. Gas analyses during the field test showed very low levels of SOX (less than or equal to 1 ppM) in the generator gaseous effluent. The SOX and NOX data did not permit any conclusion to be drawn regarding reservoir scrubbing. Appreciable levels of CO (less than or equal to 5%) were measured at the generator, and in this case produced-gas analyses showed evidence of significant gas scrubbing. 64 figures, 10 tables.

  11. Analysis of mitigating measures during steam/hydrogen distributions in nuclear reactor containments with the 3D field code gasflow

    International Nuclear Information System (INIS)

    Royl, P.; Travis, J.R.; Haytcher, E.A.; Wilkening, H.

    1997-01-01

    This paper reports on the recent model additions to the 3D field code GASFLOW and on validation and application analyses for steam/hydrogen transport with inclusion of mitigation measures. The results of the 3D field simulation of the HDR test E11.2 are summarized. Results from scoping analyses that simulate different modes of CO2 inertization for conditions from the HDR test T31.5 are presented. The last part discusses different ways of recombiner modeling during 3D distribution simulations and gives the results from validation calculations for the HDR recombiner test E11.8.1 and the Battelle test MC3. The results demonstrate that field code simulations with computer codes like GASFLOW are feasible today for complex containment geometries and that they are necessary for a reliable prediction of hydrogen/steam distribution and mitigation effects. (author)

  12. Magnitude and Rupture Area Scaling Relationships of Seismicity at The Northwest Geysers EGS Demonstration Project

    Science.gov (United States)

    Dreger, D. S.; Boyd, O. S.; Taira, T.; Gritto, R.

    2017-12-01

    Enhanced Geothermal System (EGS) resource development requires knowledge of subsurface physical parameters to quantify the evolution of fracture networks. Spatio-temporal source properties, including source dimension, rupture area, slip, rupture speed, and slip velocity of induced seismicity are of interest at The Geysers geothermal field, northern California to map the coseismic facture density of the EGS swarm. In this investigation we extend our previous finite-source analysis of selected M>4 earthquakes to examine source properties of smaller magnitude seismicity located in the Northwest Geysers Enhanced Geothermal System (EGS) demonstration project. Moment rate time histories of the source are found using empirical Green's function (eGf) deconvolution using the method of Mori (1993) as implemented by Dreger et al. (2007). The moment rate functions (MRFs) from data recorded using the Lawrence Berkeley National Laboratory (LBNL) short-period geophone network are inverted for finite-source parameters including the spatial distribution of fault slip, rupture velocity, and the orientation of the causative fault plane. The results show complexity in the MRF for the studied earthquakes. Thus far the estimated rupture area and the magnitude-area trend of the smaller magnitude Geysers seismicity is found to agree with the empirical relationships of Wells and Coppersmith (1994) and Leonard (2010), which were developed for much larger M>5.5 earthquakes worldwide indicating self-similar behavior extending to M2 earthquakes. We will present finite-source inversion results of the micro-earthquakes, attempting to extend the analysis to sub Mw, and demonstrate their magnitude-area scaling. The extension of the scaling laws will then enable the mapping of coseismic fracture density of the EGS swarm in the Northwest Geysers based on catalog moment magnitude estimates.

  13. Instrumental system for the quick relief of surface temperatures in fumaroles fields and steam heated soils

    Science.gov (United States)

    Diliberto, Iole; Cappuzzo, Santo; Inguaggiato, Salvatore; Cosenza, Paolo

    2014-05-01

    We present an instrumental system to measure and to map the space variation of the surface temperature in volcanic fields. The system is called Pirogips, its essential components are a Pyrometer and a Global Position System but also other devices useful to obtain a good performance of the operating system have been included. In the framework of investigation to define and interpret volcanic scenarios, the long-term monitoring of gas geochemistry can improve the resolution of the scientific approaches by other specific disciplines. Indeed the fluid phase is released on a continuous mode from any natural system which produces energy in excess respect to its geological boundaries. This is the case of seismic or magmatic active areas where the long-term geochemical monitoring is able to highlight, and to follow in real time, changes in the rate of energy release and/or in the feeding sources of fluids, thus contributing to define the actual behaviour of the investigated systems (e.g. Paonita el al., 2013; 2002; Taran, 2011; Zettwood and Tazieff, 1973). The demand of pirogips starts from the personal experience in long term monitoring of gas geochemistry (e.g. Diliberto I.S, 2013; 2011; et al., 2002; Inguaggiato et al.,2012a, 2012b). Both space and time variation of surface temperature highlight change of energy and mass release from the deep active system, they reveal the upraise of deep and hot fluid and can be easily detected. Moreover a detailed map of surface temperature can be very useful for establishing a network of sampling points or installing a new site for geochemical monitoring. Water is commonly the main component of magmatic or hydrothermal fluid release and it can reach the ground surface in the form of steam, as in the high and low temperature fumaroles fields, or it can even condense just below the ground surface. In this second case the water disperses in pores or circulates in the permeable layers while the un-condensable gases reach the surface (e

  14. Field test of two high-pressure, direct-contact downhole steam generators. Volume I. Air/diesel system

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, B.W.

    1983-05-01

    As a part of the Project DEEP STEAM to develop technology to more efficiently utilize steam for the recovery of heavy oil from deep reservoirs, a field test of a downhole steam generator (DSG) was performed. The DSG burned No. 2 diesel fuel in air and was a direct-contact, high pressure device which mixed the steam with the combustion products and injected the resulting mixture directly into the oil reservoir. The objectives of the test program included demonstration of long-term operation of a DSG, development of operational methods, assessment of the effects of the steam/combustion gases on the reservoir and comparison of this air/diesel DSG with an adjacent oxygen/diesel direct contact generator. Downhole operation of the air/diesel DSG was started in June 1981 and was terminated in late February 1982. During this period two units were placed downhole with the first operating for about 20 days. It was removed, the support systems were slightly modified, and the second one was operated for 106 days. During this latter interval the generator operated for 70% of the time with surface air compressor problems the primary source of the down time. Thermal contact, as evidenced by a temperature increase in the production well casing gases, and an oil production increase were measured in one of the four wells in the air/diesel pattern. Reservoir scrubbing of carbon monoxide was observed, but no conclusive data on scrubbing of SO/sub x/ and NO/sub x/ were obtained. Corrosion of the DSG combustor walls and some other parts of the downhole package were noted. Metallurgical studies have been completed and recommendations made for other materials that are expected to better withstand the downhole combustion environment. 39 figures, 8 tables.

  15. Anatomy of Old Faithful from subsurface seismic imaging of the Yellowstone Upper Geyser Basin

    KAUST Repository

    Wu, Sin-Mei; Ward, Kevin M.; Farrell, Jamie; Lin, Fan-Chi; Karplus, Marianne; Smith, Robert B.

    2017-01-01

    The Upper Geyser Basin in Yellowstone National Park contains one of the highest concentrations of hydrothermal features on Earth including the iconic Old Faithful geyser. Although this system has been the focus of many geological, geochemical

  16. Evaluation and field validation of Eddy-Current array probes for steam generator tube inspection

    International Nuclear Information System (INIS)

    Dodd, C.V.; Pate, J.R.

    1996-07-01

    The objective of the Improved Eddy-Current ISI for Steam Generator Tubing program is to upgrade and validate eddy-current inspections, including probes, instrumentation, and data processing techniques for inservice inspection of new, used, and repaired steam generator tubes; to improve defect detection, classification, and characterization as affected by diameter and thickness variations, denting, probe wobble, tube sheet, tube supports, copper and sludge deposits, even when defect types and other variables occur in combination; to transfer this advanced technology to NRC's mobile NDE laboratory and staff. This report describes the design of specialized high-speed 16-coil eddy-current array probes. Both pancake and reflection coils are considered. Test results from inspections using the probes in working steam generators are given. Computer programs developed for probe calculations are also supplied

  17. Review on Dutch-German steam generator safety activities in the field of SNR-development

    International Nuclear Information System (INIS)

    Dumm, K.; Westenbrugge, J.K. van

    1984-01-01

    This paper reviews the results of the experimental and theoretical safety related work for SNR steam generators in brief. A review of the operating experience with SNR-300 sodium-water heat-exchangers and protection philosophy used in SNR-2 is also given

  18. Low-Q structure related to partially saturated pores within the reservoir beneath The Geysers area in the northern California

    Science.gov (United States)

    Matsubara, M.

    2011-12-01

    A large reservoir is located beneath The Geysers geothermal area, northern California. Seismic tomography revealed high-velocity (high-V) and low-Vp/Vs zones in the reservoir (Julian et al., 1996) and a decrease of Vp/Vs from 1991 to 1998 (Guasekera et al., 2003) owing to withdrawal of steam from the reservoir. I perform attenuation tomography in this region to investigate the state of vapor and liquid within the reservoir. The target region, 38.5-39.0°N and 122.5-123°W, covers The Geysers area. I use seismograms of 1,231 events whose focal mechanism are determined among 65,810 events recorded by the Northern California Earthquake Data Center from 2002 to 2008 in the target region. The band-pass filtered seismograms are analyzed for collecting the maximum amplitude data. There are 26 stations that have a three-component seismometer among 47 seismic stations. I use the P- and S-wave maximum amplitudes during the two seconds after the arrival of those waves in order to avoid coda effects. A total of 8,545 P- and 1,168 S-wave amplitude data for 949 earthquakes recorded at 47 stations are available for the analysis using the attenuation tomographic method derived from the velocity tomographic method (Matsubara et al., 2005, 2008) in which spatial velocity correlation and station corrections are introduced to the original code of Zhao et al. (1992). I use 3-D velocity structure obtained by Thurber et al. (2009). The initial Q value is set to 150, corresponding to the average Q of the northern California (Ford et al., 2010). At sea level, low-Q zones are found extending from the middle of the steam reservoir within the main greywacke to the south part of the reservoir. At a depth of 1 km below sea level, a low-Q zone is located solely in the southern part of the reservoir. However, at a depth of 2 km a low-Q zone is located beneath the northern part of the reservoir. At depths of 1 to 3 km a felsite batholith in the deeper portions of the reservoir, and it corresponds

  19. Southeast Regional Wastewater Treatment Plant Facilities Improvements Project and Geysers Effluent Pipeline Project. Draft EIR/EIS, Volume 1 of 2

    International Nuclear Information System (INIS)

    1994-01-01

    The primary focus of this environmental analysis is on improvements to the Southeast Regional Wastewater Treatment Plant (SRWTP) facilities and disposal to the Geysers for injection. This analysis will be incorporated with an earlier EIR which evaluated system improvements to the SRWTP and twelve disposal alternatives. In July 1993, the Lake County Sanitation District Board of Directors (LACOSAN) selected the Geysers Effluent Pipeline as the preferred alternative to be analyzed in this EIR/EIS. This environmental analysis will primarily focus on improvements to the SRWTP facilities and a 24 inch pipeline designed to carry up to 5,400 gallons per minute of secondarily treated wastewater. The wastewater will be transported from the Lake County Sanitation District's Southeast Regional Wastewater Treatment Plant, Middletown Wastewater Treatment Plant with additional make-up water from Clear Lake to the Southeast portion of the Geysers Geothermal Field in Lake and Sonoma Counties, California

  20. Low-Q structure beneath The Geysers area in the northern California

    Science.gov (United States)

    Matsubara, M.

    2010-12-01

    A large reservoir is located beneath The Geysers geothermal area, northern California. Seismic tomography revealed high-velocity (high-V) and low-Vp/Vs zones in the reservoir (Julian et al., 1996) and a decrease of Vp/Vs from 1991 to 1998 (Guasekera et al., 2003) due to withdrawal of steam from the reservoir. I build on these earlier studies by performing the attenuation tomography in this region to investigate the Q structure. The target region, 38.5-39.0°N and 122.5-123°W, covers The Geysers area. I use seismographs of Northern California Earthquake Data Center, which recorded 1235 earthquakes with magnitude larger than 2.0 and resolved focal mechanisms from 2002 to 2008. The band-pass filtered seismographs are analyzed for collecting the maximum amplitude data. Three kinds of Butterworth band-pass filters, such as 1-3, 3-7, and 7-15, correspond to the analysis of the Q structure for 2, 5, and 10 Hz, respectively. I use the P- and S-wave maximum amplitudes between the two seconds after the arrival of those waves in order to avoid the effects by coda. A total of 8980 P- and 1086 S-wave amplitude data for 949 earthquakes recorded at 48 stations are available for the analysis using the attenuation tomographic method (Zao et al., 1996). Extremely low-Qp and Qs zones are found at the northwestern (NW) of The Geysers area at sea level. These zones are consistent with the high-Vp and Vs and low-Vp/Vs zones located at the NW part of the reservoir. The low-Qs zone extends to the southeast (SE) and with approximately 15 km length and 5 km width and has another negative peak beneath the SE part of the reservoir. This low-Qs zone is also consistent with the high-Vp and Vs regions of the reservoir characterized by a low-Vp/Vs zone. However, Qp in the SE part is slightly high. Below sea level in The Geysers reservoir, there are a main greywacke layer and a felsite layer. Above sea level, there is a greenstone melange beneath the NW extremely low-Qp and Qs region and a

  1. Field experience of cleanliness inspection for secondary-side in PWR steam generators

    International Nuclear Information System (INIS)

    Ding Xunshen

    1997-05-01

    The mechanical cleaning and TV inspection technology for secondary-side in steam generators of Daya Bay Nuclear Power Plant has been used for preventing the heat transfer tubes from damage caused by residues in steam generator and foreign objects. A lancing has been used for steam generators. The high-pressure jet sent from the central lane to the inside of the bundle has two objectives: (a) the mechanical energy in the jet breaks up the deposit, and (b) the particles are then carried to the periphery of the generator, where they are collected by a water circulation system. The TV inspection consists of the inspection before lancing and after lancing. The former includes the inspection of outer tube lane and central tube lane, and the extraction of foreign objects; the latter includes the inspection of inter tube area, outer tube lane and central tube lane, and the extraction of foreign objects. Video cassette are visualized by a specialist who is qualified to realize a map representative of the cleanliness state of the tubesheet, and to judge if it is or not acceptable. The TV inspection obtained a cleanliness conclusion according to acceptance criteria. So, it is important to work out cleanliness acceptance criteria suit for every operation stages. The site practices shown that after lancing, although hard deposit existed and height of hard deposit in some local place exceeded 5 mm, but the sludge remaining on tubesheet was less. If we can conduct periodic lancing to steam generator, the increase rate of hard deposit will be small. (7 refs., 12 figs.)

  2. Monitoring and Characterizing the Geysering and Seismic Activity at the Lusi Mud Eruption Site, East Java, Indonesia

    Science.gov (United States)

    Karyono, Karyono; Obermann, Anne; Mazzini, Adriano; Lupi, Matteo; Syafri, Ildrem; Abdurrokhim, Abdurrokhim; Masturyono, Masturyono; Hadi, Soffian

    2016-04-01

    The Lusi eruption began on May 29, 2006 in the northeast of Java Island, Indonesia, and to date is still active. Lusi is a newborn sedimentary-hosted hydrothermal system characterized by continuous expulsion of liquefied mud and breccias and geysering activity. Lusi is located upon the Watukosek fault system, a left lateral wrench system connecting the volcanic arc and the bakarc basin. This fault system is still periodically reactivated as shown by field data. In the framework of the Lusi Lab project (ERC grant n° 308126) we conducted several types of monitoring. Based on camera observations, we characterized the Lusi erupting activity by four main behaviors occurring cyclically: (1) Regular activity, which consists in the constant emission of water and mud breccias (i.e. viscous mud containing clay, silt, sand and clasts) associated with the constant expulsion of gas (mainly aqueous vapor with minor amounts of CO2 and CH4) (2) Geysering phase with intense bubbling, consisting in reduced vapor emission and more powerful bursting events that do not seem to have a regular pattern. (3) Geysering phase with intense vapor and degassing discharge and a typically dense plume that propagates up to 100 m height. (4) Quiescent phase marking the end of the geysering activity (and the observed cycle) with no gas emissions or bursts observed. To investigate the possible seismic activity beneath Lusi and the mechanisms controlling the Lusi pulsating behaviour, we deployed a network of 5 seismic stations and a HD camera around the Lusi crater. We characterize the observed types of seismic activity as tremor and volcano-tectonic events. Lusi tremor events occur in 5-10 Hz frequency band, while volcano tectonic events are abundant in the high frequencies range from 5 Hz until 25 Hz. We coupled the seismic monitoring with the images collected with the HD camera to study the correlation between the seismic tremor and the different phases of the geysering activity. Key words: Lusi

  3. Wyle Prof H G Viljoen | Geyser | HTS Teologiese Studies ...

    African Journals Online (AJOL)

    HTS Teologiese Studies / Theological Studies. Journal Home · ABOUT · Advanced Search · Current Issue · Archives · Journal Home > Vol 9, No 2 (1953) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Wyle Prof H G Viljoen. A S Geyser. Abstract. No Abstract ...

  4. Design and field operation of 1175 MW steam turbine for Ohi Nuclear Power Station

    International Nuclear Information System (INIS)

    Hirota, Yoshio; Nakagami, Yasuo; Fujii, Hisashi; Shibanai, Hirooki.

    1980-01-01

    Two 1175 MW steam turbine and generator units have been successfully in commercial operation since March 1979 and December 1979 respectively at Ohi Nuclear Power Station of the Kansai Electric Power Company. Those units, the largest in their respective outputs in Japan, have also such remarkable design features as two-stage reheat, nozzle governing turbine, water cooled generator stator and turbine-driven feedwater pumps. This paper covers design features and some topics of various pre-operational tests of the above-mentioned units. (author)

  5. Design and field operation of 1175 MW steam turbine for Ohi Nuclear Power Station

    International Nuclear Information System (INIS)

    Hirota, Y.; Nakagami, Y.; Fujii, H.; Shibanai, H.

    1980-01-01

    Two 1,175 MW steam turbine and generator units have been successfully in commercial operation since March 1979 and December 1979 respectively at Ohi Nuclear Power Station of the Kansai Electric Power Company. Those units, the largest in their respective outputs in Japan, have also such remarkable design features as two-stage reheat, nozzle governing turbine, water cooled generator stator and turbine-driven feedwater pumps. This paper covers design features and some topics of various pre-operational tests of the above-mentioned units. (author)

  6. Calculation of temperature fields formed in induction annealing of closing welded joint of jacket of steam generator for WWER 440 type nuclear power plant using ICL 2960 computer

    International Nuclear Information System (INIS)

    Sajnar, P.; Fiala, J.

    1983-01-01

    The problems are discussed of the mathematical description and simulation of temperature fields in annealing the closing weld of the steam generator jacket of the WWER 440 nuclear power plant. The basic principles are given of induction annealing, the method of calculating temperature fields is indicated and the mathematical description is given of boundary conditions on the outer and inner surfaces of the steam generator jacket for the computation of temperature fields arising during annealing. Also described are the methods of determining the temperature of exposed parts of heat exchange tubes inside the steam generator and the technical possibilities are assessed of the annealing equipment from the point of view of its computer simulation. Five alternatives are given for the computation of temperature fields in the area around the weld for different boundary conditions. The values are given of maximum differences in the temperatures of the metal in the annealed part of the steam generator jacket which allow the assessment of individual computation variants, this mainly from the point of view of observing the course of annealing temperature in the required width of the annealed jacket of the steam generator along both sides of the closing weld. (B.S.)

  7. Feasibility to apply the steam assisted gravity drainage (SAGD) technique in the country's heavy crude-oil fields

    International Nuclear Information System (INIS)

    Rodriguez, Edwin; Orjuela, Jaime

    2004-01-01

    The steam assisted gravity drainage (SAGD) processes are one of the most efficient and profitable technologies for the production of heavy crude oils and oil sands. These processes involve the drilling of a couple of parallel horizontal wells, separated by a vertical distance and located near the oil field base. The upper well is used to continuously inject steam into the zone of interest, while the lower well collects all resulting fluids (oil, condensate and formation water) and takes them to the surface (Butler, 1994). This technology has been successfully implemented in countries such as Canada, Venezuela and United States, reaching recovery factors in excess of 50%. This article provides an overview of the technique's operation mechanism and the process most relevant characteristics, as well as the various categories this technology is divided into, including all its advantages and limitations. Furthermore, the article sets the oil field's minimal conditions under which the SAGD process is efficient, which conditions, as integrated to a series of mathematical models, allow to make forecasts on production, thermal efficiency (ODR) and oil to be recovered, as long as it is feasible (from a technical point of view) to apply this technique to a defined oil field. The information and concepts compiled during this research prompted the development of software, which may be used as an information, analysis and interpretation tool to predict and quantify this technology's performance. Based on the article, preliminary studies were started for the country's heavy crude-oil fields, identifying which provide the minimum conditions for the successful development of a pilot project

  8. PWSCC of steam generator divider plates in alloy 600: coupling field characterizations with R-D studies

    International Nuclear Information System (INIS)

    Couvant, T.; Vaillant, F.; Miloudi, S.; Deforge, D.; Thebault, Y.

    2011-01-01

    Some IGSCC (Intergranular Stress Corrosion Cracks) indications have been observed at the cold work surface of the hot side (325 C) of some divider plates of steam generators (SG) since 2002. Based on many in-service inspection campaigns (about 100 SG inspections), no evidence of propagation following the first detection has never been observed. In this context, crack propagation tests were carried out in EDF in order to evaluate the susceptibility to SCC of warm rolled plates made of Alloy 600 as a function of the degree of cold work. Some results recently obtained in the EDF Hot Laboratories on the decommissioned SG1 of Chinon B1 were coupled with calibrated crack propagation laws on cold worked materials. Results enlightened the restricted susceptibility to observe a significant crack depth over the steam generator lifetime. Along the most probable crack growth path, the maximal crack growth rate (CGR) was lower than 300 μm.cycle -1 and the CGR did not exceed 260 μm.cycle -1 as soon as the local plastic deformation was lower than 0.07. A laboratory SCC test on a specimen with a superficial cold worked layer confirmed the good resistance to SCC when the local plastic strain was lower than 0.07, in good agreement with the field experience. (authors)

  9. Review on Japanese activities in the field of maintenance and repair of LMFBR steam generators

    International Nuclear Information System (INIS)

    Tsuchiya, T.; Fukuda, T.; Sato, M.; Okabayashi, K.; Takahashi, T.

    2002-01-01

    Summary of Japanese activities on maintenance and repair of LMFBR steam generators (SG) is described in this paper. The concept (adoption of helical coil tube etc.) of MONJU SG was established in conceptional design started from 1968, and research and development (R and D) program was prepared. Parallel with basic studies such as material, welding, sodium water reaction and etc., overall verification tests using mock up SGs were conducted. As the first step, 1 Mw SG with two active helical tubes (and eight dummy tubes) was fabricated and operated, and many maintenance and repair experiences were accumulated through two small water leak troubles. Two 50Mw SGs, 1/5 scale of MONJU SG, were constructed and operated for long time. Post test examinations were carried out for No.1 50 Mw SG and feasibility of this type of SG was confirmed. In regard to maintenance and repair techniques, explosive and welding method for tube plugging and UT and ECT techniques for inspection of tube integrity are under development. Overall verification test for on-site and in-factory maintenance and repair techniques was conducted using No.2 50Mw SG evaporator and applicability of those techniques to real plant was evaluated. Many experiences were accumulated for removal and cleaning of sodium water reaction products after sodium water reaction in the cooling system and pressure relief system, using the Large Sodium Water Reaction Test Facility (SWAT-1 and 3). (author)

  10. Heretic or rebel? The heresy trial of Albert Geyser

    Directory of Open Access Journals (Sweden)

    Wim Dreyer

    2016-11-01

    Full Text Available During September 1961, a charge of heresy was laid against New Testament scholar and antiapartheid activist Prof. A.S. (Albert Geyser. The charge was brought by three senior theological students of the University of Pretoria. They accused Geyser of interpreting Philippians 2 in such a way that it undermined the church’s doctrine of Christ’s pre-existence. The heresy trial started on 24 October 1961 under massive public interest. The trial lasted 6 months and the proceedings covered 2672 typed pages. Reporters of 25 national and international newspapers attended the trial. The heresy trial caused widespread international condemnation of what was regarded as an orchestrated attempt to get rid of Geyser, because of his public and radical opposition to apartheid. In this contribution, Geyser’s theological critique of apartheid as well as his conviction of heresy is discussed. The proceedings of the trial, minutes of the moderature, media coverage and Geyser’s publications serve as primary sources. It concludes with a critical evaluation of Geyser’s theology and his role as a public theologian.

  11. Analysis of steam turbine boresonic NDE data using a field portable computer

    International Nuclear Information System (INIS)

    Leon-Salamanca, T.; Reinhart, E.R.

    2004-01-01

    Due to the high combined stress caused by thermal and rotational loading, the highest stress in the hollow rotor forging of typical nuclear power steam turbine and generator units is in the region at or near the bore. Material discontinuities aligned along the axis of the rotor centerline, with depth in the radial plane of the rotor, have the highest probability of becoming flaws of concern to the integrity of the rotor. Due to the nature of the casting/forging process a great number of material discontinuities can be found near the rotor bore. During the ultrasonic examination of rotors with a large number of discontinuities, the engineer must determine if these discontinuities are ultrasonic reflectors caused by fabrication anomalies, reflectors that are probably fabrication discontinuities but in such close proximity that they may link up and form a defect of concern to future operation, or reflectors that have significant size and are real growing flaws, but may appear as separated indications. Until recently, plotting of ultrasonic data to determine the significance of closely spaced indications was time consuming and required special 3-D analysis methods to determine if indications were isolated or linked to form larger discontinuities. To overcome this problem, a software program, compatible with portable personal computers, was written to define a parameter necessary for determining if a group of indications detected from nondestructive ultrasonic testing of turbine and generator rotors could combine to form larger ones. The approach involved using a computer algorithm to model each indication as a three dimensional sphere with a diameter equal to the ultrasonic signal amplitude from an equivalent flat bottom hole reflector and setting a minimum gap distance between spheres necessary for a link up. The program was implemented following a commonly used data format accepted by industry recognized computer codes. The gap distance and link up parameters were

  12. Steaming ahead

    International Nuclear Information System (INIS)

    Anon.

    1997-01-01

    An example of the development of geothermal power in Indonesia is described. Wells are being drilled into the Salak volcano on Java, about 60km south of Jakarta. These let out high pressure hot water trapped 1 to 3km below the surface which can be flashed into steam for driving turbines. The hot water field has already produced 110MW of power since 1994 and is currently being expanded to 330MW. Some details of the drilling and civil engineering are given. Since Indonesia sits on the edge of giant tectonic boundary known as the ''Pacific ring of fire'', the potential for further development is enormous. Ultimately volcanic activity could release an estimated 27,000MW capacity. More realistically, 2,000MW of crustal power by 2020 is spoken of. (UK)

  13. Evaluation and Demonstration of a Mobile Steam Applicator to Disinfest Soil in Field-grown California Strawberry and Flower Production

    Science.gov (United States)

    Steam can effectively kill soil borne pests if soil temperatures can be raised to 70 °C for 20 min. The Ferrari Sterilter is capable of generating super heated steam to reach these temperatures within 5 to 7 min. Frontal plates on the machine allow it to thoroughly heat the soil to 30 cm depth, gran...

  14. Field trial of a fast single-pass transmit-receive probe during Gentilly II steam generator tube inspection

    International Nuclear Information System (INIS)

    Obrutsky, L.; Cantin, M.; Renaud, J.; Cecco, V.; Lakhan, R.; Sullivan, S.

    2000-01-01

    A new generation of transmit-receive single-pass probes, denoted as C6 or X probe, was field tested during the Gentilly II, 2000 steam generator tube inspection. This probe has a performance equivalent to rotating probes and can be used for tubesheet and full-length inspection at an inspection speed equivalent to that of bobbin probes. Existing C3 transmit-receive probes have been demonstrated to be effective in detecting circumferential cracks. The C5 probe can detect both circumferential and axial cracks and volumetric defects but cannot discriminate between them. The C6 probe expands on the capabilities of both probes in a single probe head. It can simultaneously detect and discriminate between circumferential and axial cracks to satisfy different plugging criteria. It has excellent coverage, good defect detectability, and improved sizing and characterization. Probe data is displayed in C-scan format so that the amount of data to be analyzed is similar to rotating probes. The C6 probe will significantly decrease inspection time and the need for re-inspection and tube pulling. This paper describes the advantages of the probe and demonstrates its capabilities employing signals from tube samples with calibration flaws and laboratory induced cracks. It shows the results from the field trial of the probe at Gentilly II and describes the instrumentation, hardware and software used for the inspection. (author)

  15. Field trial of a fast single-pass transmit-receive probe during Gentilly II steam generator tube inspection

    International Nuclear Information System (INIS)

    Obrutsky, L.; Cantin, M.; Renaud, J.; Cecco, V.; Lakhan, R.; Sullivan, S.

    2000-01-01

    A new generation of transmit-receive single-pass probes, denoted as C6 or X probe, was field-tested during the Gentilly II, 2000 steam generator tube inspection. This probe has a performance equivalent to rotating probes and can be used for tubesheet and full-length inspection at an inspection speed equivalent to that of bobbin probes. Existing C3 transmit-receive probes have been demonstrated to be effective in detecting circumferential cracks. The C5 probe can detect both circumferential and axial cracks and volumetric defects but cannot discriminate between them. The C6 probe expands on the capabilities of both probes in a single probe head. It can simultaneously detect and discriminate between circumferential and axial cracks to satisfy different plugging criteria. It has excellent coverage, good defect detectability, and improved sizing and characterization. Probe data is displayed in C-scan format so that the amount of data to be analyzed is similar to rotating probes. The C6 probe will significantly decrease inspection time and the need for re-inspection and tube pulling. This paper describes the advantages of the probe and demonstrates its capabilities employing signals from tube samples with calibration flaws and laboratory induced cracks. It shows the results from the field trial of the probe at Gentilly II and describes the instrumentation, hardware and software used for the inspection. (author)

  16. Chemical analyses of waters from geysers, hot springs, and pools in Yellowstone National Park, Wyoming from 1974 to 1978

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, J.M.; Yadav, S.

    1979-01-01

    Waters from geysers, hot springs, and pools of Yellowstone National Park have been analyzed. We report 422 complete major ion analyses from 330 different locations of geysers, hot springs, and pools, collected from 1974 to 1978. Many of the analyses from Upper, Midway, Lower, and Norris Geyser Basin are recollections of features previously reported.

  17. Steam drums

    International Nuclear Information System (INIS)

    Crowder, R.

    1978-01-01

    Steam drums are described that are suitable for use in steam generating heavy water reactor power stations. They receive a steam/water mixture via riser headers from the reactor core and provide by means of separators and driers steam with typically 0.5% moisture content for driving turbines. The drums are constructed as prestressed concrete pressure vessels in which the failure of one or a few of the prestressing elements does not significantly affect the overall strength of the structure. The concrete also acts as a radiation shield. (U.K.)

  18. Techniques for processing remote field eddy current signals from bend regions of steam generator tubes of prototype fast breeder reactor

    Energy Technology Data Exchange (ETDEWEB)

    Thirunavukkarasu, S. [Non Destructive Evaluation Division, Indira Gandhi Centre for Atomic Research, Kalpakkam, TN 603 102 (India); Rao, B.P.C., E-mail: bpcrao@igcar.gov.in [Non Destructive Evaluation Division, Indira Gandhi Centre for Atomic Research, Kalpakkam, TN 603 102 (India); Jayakumar, T.; Raj, Baldev [Non Destructive Evaluation Division, Indira Gandhi Centre for Atomic Research, Kalpakkam, TN 603 102 (India)

    2011-04-15

    Steam generator (SG) is one of the most critical components of sodium cooled fast breeder reactor. Remote field eddy current (RFEC) technique has been chosen for in-service inspection (ISI) of these ferromagnetic SG tubes made of modified 9Cr-1Mo steel (Grade 91). Expansion bends are provided in the SGs to accommodate differential thermal expansion. During ISI using RFEC technique, in expansion bend regions, exciter-receiver coil misalignment, bending stresses, probe wobble and magnetic permeability variations produce disturbing noise hindering detection of defects. Fourier filtering, cross-correlation and wavelet transform techniques have been studied for noise reduction as well as enhancement of RFEC signals of defects in bend regions, having machined grooves and localized defects. Performance of these three techniques has been compared using signal-to-noise ratio (SNR). Fourier filtering technique has shown better performance for noise reduction while cross-correlation technique has resulted in significant enhancement of signals. Wavelet transform technique has shown the combined capability of noise reduction and signal enhancement and resulted in unambiguous detection of 10% of wall loss grooves and localized defects in the bend regions with SNR better than 7 dB.

  19. The steam condensate alteration mineralogy of Ruatapu cave, Orakei Korako geothermal field, Taupo Volcanic Zone, New Zealand

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, K.A.; Hamlin, K.A.; Browne, P.R.L.; Campbell, K.A. [Aukland Univ., Dept. of Geology, Auckland (New Zealand); Martin, R.

    2000-02-01

    Ruatapu cave has developed beneath a block of hydrothermally altered quaternary vitric tuff in the active Orakei Korako geothermal field. The cave extends {approx}45 m, with a vertical drop of 23 m, to a shallow pool of clear, sulfate-rich ({approx}450 {mu}g/g), warm (T = 43-48degC), acid (pH 3.0) water. Steam, accompanied by H{sub 2}S, rises from the pool surface, from a second pool nearby, and from fumaroles and joints in the ignimbrite, to condense on surfaces within the cave. Oxidation of the H{sub 2}S to H{sub 2}SO{sub 4} produces acid sulfate fluids which react with the surficial rocks to generate three principal and distinct assemblages of secondary minerals. Kaolinite {+-} opal-A {+-} cristobalite {+-} alunite {+-} alunogen dominate the assemblage at the cave mouth; the essential Al, K and Si are derived from the tuffs and Na, Ca, Fe and Mg removed. In the main body of the cave the highly limited throughflow of water results in the more soluble of the leached constituents, notably Na and K, being retained in surface moisture and becoming available to form tamarugite and potash alum as efflorescences, in part at the expense of kaolin, along with lesser amounts of alunogen, meta-alunogen, mirabilite, halotrichite, kalinite, gypsum and, possibly, tschermigite; the particular species being determined by the prevailing physico-chemical conditions. Heat and moisture assist in moving Fe out of the rock to the air-water interface but, unlike typical surficial acid alteration systems elsewhere in the TVZ, there is an insufficient flow of water, of appropriate Eh-pH, to continue to move Fe out of the cave system. Much becomes locally immobilised as Fe oxides and oxyhydroxides that mottle the side and roof of the cave. Jarosite crusts have developed where acid sulfate pool waters have had protracted contact with ignimbrite wallrock coated with once-living microbial mats. Subsequent lowering of the waters has caused the porous jarositic crusts to alter to potatsh alum

  20. Steam 80 steam generator instrumentation

    International Nuclear Information System (INIS)

    Carson, W.H.; Harris, H.H.

    1980-01-01

    This paper describes two special instrumentation packages in an integral economizer (preheater) steam generator of one of the first System 80 plants scheduled to go into commercial operation. The purpose of the instrumentation is to obtain accurate operating information from regions of the secondary side of the steam generator inaccessible to normal plant instrumentation. In addition to verification of the System 80 steam generator design predictions, the data obtained will assist in verification of steam generator thermal/hydraulic computer codes developed for generic use in the industry

  1. Selling steam

    International Nuclear Information System (INIS)

    Zimmer, M.J.; Goodwin, L.M.

    1991-01-01

    This article addresses the importance of steam sales contract is in financing cogeneration facilities. The topics of the article include the Public Utility Regulatory Policies Act provisions and how they affect the marketing of steam from qualifying facilities, the independent power producers market shift, and qualifying facility's benefits

  2. Steam generator

    International Nuclear Information System (INIS)

    Fenet, J.-C.

    1980-01-01

    Steam generator particularly intended for use in the coolant system of a pressurized water reactor for vaporizing a secondary liquid, generally water, by the primary cooling liquid of the reactor and comprising special arrangements for drying the steam before it leaves the generator [fr

  3. Steam condenser

    International Nuclear Information System (INIS)

    Masuda, Fujio

    1980-01-01

    Purpose: To enable safe steam condensation by providing steam condensation blades at the end of a pipe. Constitution: When high temperature high pressure steam flows into a vent pipe having an opening under water in a pool or an exhaust pipe or the like for a main steam eacape safety valve, non-condensable gas filled beforehand in the steam exhaust pipe is compressed, and discharged into the water in the pool. The non-condensable gas thus discharged from the steam exhaust pipe is introduced into the interior of the hollow steam condensing blades, is then suitably expanded, and thereafter exhausted from a number of exhaust holes into the water in the pool. In this manner, the non-condensable gas thus discharged is not directly introduced into the water in the pool, but is suitable expanded in the space of the steam condensing blades to suppress extreme over-compression and over-expansion of the gas so as to prevent unstable pressure vibration. (Yoshihara, H.)

  4. Applications of field portable computers to NDE of nuclear power plant steam turbine/generator rotors, discs, and retaining rings

    International Nuclear Information System (INIS)

    Reinhart, E.R.; Leon-Salamanca, T.

    2004-01-01

    The new generation of compact, powerful portable computers have been incorporated into a number of nondestructive evaluation (NDE) systems used to inspect critical areas of the steam turbine and generator units of nuclear power plants. Due to the complex geometry of turbine rotors, generator rotors, retaining rings, and shrunk-on turbine discs, the computers are needed to rapidly calculate the optimum position of an ultrasonic transducer or eddy current probe in order to detect defects at several critical areas. Examples where computers have been used to overcome problems in nondestructive evaluation include; analysis of large numbers of closely spaced near-bore ultrasonic reflectors to determine their potential for link-up in turbine and generator rotor bores, distinguishing ultrasonic crack signals from other reflectors such as the shrink-fit form reflector detected during ultrasonic scanning of shrunk-on generator retaining rings, and detection and recording of eddy current and ultrasonic signals from defects that could be missed by data acquisition systems with inadequate response. The computers are also used to control scanners to insure total inspection coverage. To facilitate the use of data from detected discontinuities in conjunction with stress and fracture mechanics analysis programs, the computers provide presentations of flaws in color and in three dimensions. The field computers have been instrumental in allowing the inspectors to develop on-site reports that enable the owner/operator to rapidly make run/repair/replace decisions. Examples of recent experiences using field portable computers in NDE systems will be presented along with anticipated future developments. (author)

  5. Determining the in situ water content of the Geysers Graywacke of Northern California

    Energy Technology Data Exchange (ETDEWEB)

    Marsh, A.

    1994-12-01

    The water content, porosity and permeability measurements of the Northern California Geysers rocks are used to predict the lifetime of the geothermal resource, which provides 10% of Northern California`s electricity. The Geysers rock was drilled from defunct well SB-15-D, and some cores wee sealed in aluminum tubes to preserve the in situ water content. These cores were sent to the Lawrence Livermore Laboratory to measure the water content. Humidity measurements were taken of the air around a one and a half foot encased core, recovered from a depth of 918.9 feet. Over a seven day period, the humidity reached almost 100% indicating that the air around the core was saturated in water vapor. We believe the sealing method is effective, preserving the in-situ water content. To measure water content, I will use Archimede`s principle to determine the density of the core before and after drying in an oven. Ultrasonic measurements will be taken of the core upon removal from aluminum tube to determine the change of p-wave velocity with change in water content. Water in the pores increases the effective compressibility of the rock therefore increasing the p-velocity. The measured p-wave velocities can then be used in the field to determine in-situ water content. Three dimensional x-ray images will be used to determine the deviations from average density within individual cores. Since the density depends on water content as well as mineralogy, images can show the location of pore fluid and drilling mud. Archimede`s principle, humidity detection, ultrasonics and x-ray scanning are viable methods to measure the in-situ water content and pore water distribution in the graywacke.

  6. Kids Inspire Kids for STEAM

    OpenAIRE

    Fenyvesi, Kristof; Houghton, Tony; Diego-Mantecón, José Manuel; Crilly, Elizabeth; Oldknow, Adrian; Lavicza, Zsolt; Blanco, Teresa F.

    2017-01-01

    Abstract The goal of the Kids Inspiring Kids in STEAM (KIKS) project was to raise students' awareness towards the multi- and transdisciplinary connections between the STEAM subjects (Science, Technology, Engineering, Arts & Mathematics), and make the learning about topics and phenomena from these fields more enjoyable. In order to achieve these goals, KIKS project has popularized the STEAM-concept by projects based on the students inspiring other students-approach and by utilizing new tec...

  7. Development of remote field ECT sensor for high temperature steam generator tubes

    International Nuclear Information System (INIS)

    Onoue, Akira; Yamada, Fumiaki; Imai, Yoshiyuki; Watanabe, Tomoo; Ozawa, Kazumasa

    2005-02-01

    Commercialized Fast Breeder Reactor (FBR)s have to achieve competitive unit price in electricity generation with other energy sources by reducing not only construction and fuel cost but also operation and maintenance cost, in order to be introduced in line with market principles. Operation and maintenance cost cannot be reduced until plant utilization factor is enhanced by shortening duration times of periodical inspections and expanding continuous operation periods. Critical paths in periodical inspections should be shortened to reduce entire duration time of a periodical inspections should be shortened to reduce entire duration time of a periodical inspection. and reduction of the inspection time is desired. Reflecting this background, as a research activity within the Feasibility Study for Future Commercialized FBRs, technology for volumetric inspection of SG heat transfer tubes in high temperature is being developed, in order to reduce the inspection time by skipping cooling down process. This report describes a series of experiments of heat-resistant remote field (RF) ECT probe to evaluate its defect detection performance on outer surface of heat transfer tubes. The results are summarized as listed below: (1) Defects can be detected in high temperature if sodium is drained, but cannot be detected if tube is submerged in liquid sodium. (2) The goal detection performance against round wall thinning is thought to be possibly achieved, because the measured S/N ratio exceeds 9.3 in detecting artificial round wall thinning with 10 mm width and depth beyond 10%. (3) Round wall slits can possibly detected because the S/N ratio exceeded 3.7 in detecting artificial round wall slits with 0.5 mm width and depth beyond 15%. (4) Defects of partial wall thinning are difficult to be detected, because the S/N ratio was less than 2.0 in detecting partial wall thinning with 10 mm width and 10 mm axial length and depth up to 20%. (5) In detecting defects of 12Cr steel tubes by

  8. Experimental study of single- and two-phase flow fields around PWR steam generator tube support plates

    International Nuclear Information System (INIS)

    Bates, J.M.; Stewart, C.W.

    1979-08-01

    Laser-Doppler anemometry (LDA) was used to measure local mean axial velocities and turbulence intnsities at selected locations within a study model dimensionally protypic of an existing PWR steam generator design. The model tube bundle with support plate was installed in a special flow housing that formed part of an isothermal recirculating water flow loop. Flow conditions for this experiment were intended to simulate only typical single-phase flow velocities and were not an attempt to completely model actual steam generator, boiling, two-phase flow conditions. The measurements were performed in water at approximately 85 0 F with test section average velocities of approximately 0.55 and 1.1 fps. These conditions corresponded to Reynolds numbers of approximately 7,000 and approximately 14,000, respectively. Normalized velocity and turbulence intensity ratios are graphically reported. Additional qualitative, photographic investigations of air-water two-phase flows in a PWR steam generator study model were also performed

  9. Steam turbines for the future

    International Nuclear Information System (INIS)

    Trassl, W.

    1988-01-01

    Approximately 75% of the electrical energy produced in the world is generated in power plants with steam turbines (fossil and nuclear). Although gas turbines are increasingly applied in combined cycle power plants, not much will change in this matter in the future. As far as the steam parameters and the maximum unit output are concerned, a certain consolidation was noted during the past decades. The standard of development and mathematical penetration of the various steam turbine components is very high today and is applied in the entire field: For saturated steam turbines in nuclear power plants and for steam turbines without reheat, with reheat and with double reheat in fossil-fired power plants and for steam turbines with and without reheat in combined cycle power plants. (orig.) [de

  10. Data analysis and analytical predictions of a steam generator tube bundle flow field for verification of 2-D T/H computer code

    International Nuclear Information System (INIS)

    Hwang, J.Y.; Reid, H.C.; Berringer, R.

    1981-01-01

    Analytical predictions of the flow field within a 60 deg segment flow model of a proposed sodium heated steam generator are compared to experimental results obtained from several axial levels between baffling. The axial/crossflow field is developed by use of alternating multi-ported baffling, accomplished by radial perforation distribution. Radial and axial porous model predictions from an axisymmetric computational analysis compared to intra-pitch experimental data at the mid baffle span location for various levels. The analytical mechanics utilizes a cylindrical, axisymmetric, finite difference model, solving conservation mass and momentum equations. 6 refs

  11. Triggering and modulation of geyser eruptions in Yellowstone National Park by earthquakes, earth tides, and weather

    Science.gov (United States)

    Hurwitz, Shaul; Sohn, Robert A.; Luttrell, Karen; Manga, Michael

    2014-01-01

    We analyze intervals between eruptions (IBEs) data acquired between 2001 and 2011 at Daisy and Old Faithful geysers in Yellowstone National Park. We focus our statistical analysis on the response of these geysers to stress perturbations from within the solid earth (earthquakes and earth tides) and from weather (air pressure and temperature, precipitation, and wind). We conclude that (1) the IBEs of these geysers are insensitive to periodic stresses induced by solid earth tides and barometric pressure variations; (2) Daisy (pool geyser) IBEs lengthen by evaporation and heat loss in response to large wind storms and cold air; and (3) Old Faithful (cone geyser) IBEs are not modulated by air temperature and pressure variations, wind, and precipitation, suggesting that the subsurface water column is decoupled from the atmosphere. Dynamic stress changes of 0.1−0.2 MPa resulting from the 2002 M-7.9 Denali, Alaska, earthquake surface waves caused a statistically significant shortening of Daisy geyser's IBEs. Stresses induced by other large global earthquakes during the study period were at least an order of magnitude smaller. In contrast, dynamic stresses of >0.5 MPa from three large regional earthquakes in 1959, 1975, and 1983 caused lengthening of Old Faithful's IBEs. We infer that most subannual geyser IBE variability is dominated by internal processes and interaction with other geysers. The results of this study provide quantitative bounds on the sensitivity of hydrothermal systems to external stress perturbations and have implications for studying the triggering and modulation of volcanic eruptions by external forces.

  12. Steam generators and furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Swoboda, E

    1978-04-01

    The documents published in 1977 in the field of steam generators for conventional thermal power plants are classified according to the following subjects: power industry and number of power plants, planning and operation, design and construction, furnaces, environmental effects, dirt accumulation and corrosion, conservation and scouring, control and automation, fundamental research, and materials.

  13. Steam-Generator Integrity Program/Steam-Generator Group Project

    International Nuclear Information System (INIS)

    1982-10-01

    The Steam Generator Integrity Program (SGIP) is a comprehensive effort addressing issues of nondestructive test (NDT) reliability, inservice inspection (ISI) requirements, and tube plugging criteria for PWR steam generators. In addition, the program has interactive research tasks relating primary side decontamination, secondary side cleaning, and proposed repair techniques to nondestructive inspectability and primary system integrity. The program has acquired a service degraded PWR steam generator for research purposes. This past year a research facility, the Steam Generator Examination Facility (SGEF), specifically designed for nondestructive and destructive examination tasks of the SGIP was completed. The Surry generator previously transported to the Hanford Reservation was then inserted into the SGEF. Nondestructive characterization of the generator from both primary and secondary sides has been initiated. Decontamination of the channelhead cold leg side was conducted. Radioactive field maps were established in the steam generator, at the generator surface and in the SGEF

  14. Steam generators

    International Nuclear Information System (INIS)

    Hayden, R.L.J.

    1979-01-01

    Steam generators for nuclear reactors are designed so that deposition of solids on the surface of the inlet side of the tubesheet or the inlet header with the consequent danger of corrosion and eventual tube failure is obviated or substantially reduced. (U.K.)

  15. Red Geyser: A New Class of Galaxy with Large-scale AGN-driven Winds

    Science.gov (United States)

    Roy, Namrata; Bundy, Kevin; Cheung, Edmond; MaNGA Team

    2018-01-01

    A new class of quiescent (non-star-forming) galaxies harboring possible AGN-driven winds have been discovered using the spatially resolved optical spectroscopy from the ongoing SDSS-IV MaNGA (Sloan Digital Sky Survey-IV Mapping Nearby Galaxies at Apache Point Observatory) survey. These galaxies named "red geysers" constitute 5%-10% of the local quiescent galaxy population and are characterized by narrow bisymmetric ionized gas emission patterns. These enhanced patterns are seen in equivalent width maps of Hα, [OIII] and other strong emission lines. They are co-aligned with the ionized gas velocity gradients but significantly misaligned with stellar velocity gradients. They also show very high gas velocity dispersions (~200 km/s). Considering these observations in light of models of the gravitational potential, Cheung et al. argued that red geysers host large-scale AGN-driven winds of ionized gas that may play a role in suppressing star formation at late times. In this work, we test the hypothesis that AGN activity is ultimately responsible for the red geyser phenomenon. We compare the nuclear radio activity of the red geysers to a matched control sample of galaxies of similar stellar mass, redshift, rest frame NUV–r color and axis ratio. and additionally, control for the presence of ionized gas. We have used 1.4 GHz radio continuum data from the VLA FIRST Survey to stack the radio flux from the red geyser sample and control sample. We find that the red geysers have a higher average radio flux than the control galaxies at > 3σ significance. Our sample is restricted to rest-frame NUV–r color > 5, thus ruling out possible radio emission due to star formation activity. We conclude that red geysers are associated with more active AGN, supporting a feedback picture in which episodic AGN activity drives large-scale but relatively weak ionized winds in many in many early-type galaxies.

  16. Protecting the Geyser Basins of Yellowstone National Park: Toward a New National Policy for a Vulnerable Environmental Resource

    Science.gov (United States)

    Barrick, Kenneth A.

    2010-01-01

    Geyser basins provide high value recreation, scientific, economic and national heritage benefits. Geysers are globally rare, in part, because development activities have quenched about 260 of the natural endowment. Today, more than half of the world’s remaining geysers are located in Yellowstone National Park, northwest Wyoming, USA. However, the hydrothermal reservoirs that supply Yellowstone’s geysers extend well beyond the Park borders, and onto two “Known Geothermal Resource Areas”—Island Park to the west and Corwin Springs on the north. Geysers are sensitive geologic features that are easily quenched by nearby geothermal wells. Therefore, the potential for geothermal energy development adjacent to Yellowstone poses a threat to the sustainability of about 500 geysers and 10,000 hydrothermal features. The purpose here is to propose that Yellowstone be protected by a “Geyser Protection Area” (GPA) extending in a 120-km radius from Old Faithful Geyser. The GPA concept would prohibit geothermal and large-scale groundwater wells, and thereby protect the water and heat supply of the hydrothermal reservoirs that support Yellowstone’s geyser basins and important hot springs. Proactive federal leadership, including buyouts of private groundwater development rights, can assist in navigating the GPA through the greater Yellowstone area’s “wicked” public policy environment. Moreover, the potential impacts on geyser basins from intrusive research sampling techniques are considered in order to facilitate the updating of national park research regulations to a precautionary standard. The GPA model can provide the basis for protecting the world’s few remaining geyser basins.

  17. Multireaction equilibrium geothermometry: A sensitivity analysis using data from the Lower Geyser Basin, Yellowstone National Park, USA

    Science.gov (United States)

    King, Jonathan M.; Hurwitz, Shaul; Lowenstern, Jacob B.; Nordstrom, D. Kirk; McCleskey, R. Blaine

    2016-01-01

    A multireaction chemical equilibria geothermometry (MEG) model applicable to high-temperature geothermal systems has been developed over the past three decades. Given sufficient data, this model provides more constraint on calculated reservoir temperatures than classical chemical geothermometers that are based on either the concentration of silica (SiO2), or the ratios of cation concentrations. A set of 23 chemical analyses from Ojo Caliente Spring and 22 analyses from other thermal features in the Lower Geyser Basin of Yellowstone National Park are used to examine the sensitivity of calculated reservoir temperatures using the GeoT MEG code (Spycher et al. 2013, 2014) to quantify the effects of solute concentrations, degassing, and mineral assemblages on calculated reservoir temperatures. Results of our analysis demonstrate that the MEG model can resolve reservoir temperatures within approximately ±15°C, and that natural variation in fluid compositions represents a greater source of variance in calculated reservoir temperatures than variations caused by analytical uncertainty (assuming ~5% for major elements). The analysis also suggests that MEG calculations are particularly sensitive to variations in silica concentration, the concentrations of the redox species Fe(II) and H2S, and that the parameters defining steam separation and CO2 degassing from the liquid may be adequately determined by numerical optimization. Results from this study can provide guidance for future applications of MEG models, and thus provide more reliable information on geothermal energy resources during exploration.

  18. Evaluation of thermal performance in fields subjected to steam injection (SW-SAGD mode), Orinoco oil belt, Venezuela

    Energy Technology Data Exchange (ETDEWEB)

    Armas, F.; Mago, R.; Franco, L.; Rodriguez, J.; Gil, E. [PDVSA EandP (Venezuela)

    2011-07-01

    The first well to operate the SW-SAGD process in the Orinoco oil belt in Venezuela was built in 2006 by Petroleos de Venezuela S.A (PDVSA). SW-SAGD is a thermal recovery process consisting in the injection of steam through a horizontal well pipe insulation. In order to follow the behavior of steam and the movement of heated fluids in such a process better, PDVSA installed a monitoring system composed of high temperature fiber optic and thermocouple type sensors. The aim of this paper is to assess the thermal behavior of reservoirs in wells under the SW-SAGD process. A pilot test has been conducted over the last 3 years. Results show an increase in production and estimations show a recovery factor twice as high as in other wells. This study demonstrated that SW-SAGD is an excellent alternative solution to stimulate reservoirs in the Orinoco oil belt and valuable information on the reservoir's thermal behavior was established.

  19. Subsurface energy storage and transport for solar-powered geysers on Triton

    Science.gov (United States)

    Kirk, Randolph L.; Soderblom, Laurence A.; Brown, Robert H.

    1990-01-01

    The location of active geyser-like eruptions and related features close to the current subsolar latitude on Triton suggests a solar energy source for these phenomena. Solid-state greenhouse calculations have shown that sunlight can generate substantially elevated subsurface temperatures. A variety of models for the storage of solar energy in a subgreenhouse layer and for the supply of gas and energy to a geyser are examined. 'Leaky greenhouse' models with only vertical gas transport are inconsistent with the observed upper limit on geyser radius of about 1.5 km. However, lateral transport of energy by gas flow in a porous N2 layer with a block size on the order of a meter can supply the required amount of gas to a source region about 1 km in radius. The decline of gas output to steady state may occur over a period comparable with the inferred active geyser lifetime of 5 earth years. The required subsurface permeability may be maintained by thermal fracturing of the residual N2 polar cap. A lower limit on geyser source radius of about 50 to 100 m predicted by a theory of negatively buoyant jets is not readily attained.

  20. Nuclear geyser model of the origin of life: Driving force to promote the synthesis of building blocks of life

    Directory of Open Access Journals (Sweden)

    Toshikazu Ebisuzaki

    2017-03-01

    Full Text Available We propose the nuclear geyser model to elucidate an optimal site to bear the first life. Our model overcomes the difficulties that previously proposed models have encountered. Nuclear geyser is a geyser driven by a natural nuclear reactor, which was likely common in the Hadean Earth, because of a much higher abundance of 235U as nuclear fuel. The nuclear geyser supplies the following: (1 high-density ionizing radiation to promote chemical chain reactions that even tar can be used for intermediate material to restart chemical reactions, (2 a system to maintain the circulation of material and energy, which includes cyclic environmental conditions (warm/cool, dry/wet, etc. to enable to produce complex organic compounds, (3 a lower temperature than 100 °C as not to break down macromolecular organic compounds, (4 a locally reductive environment depending on rock types exposed along the geyser wall, and (5 a container to confine and accumulate volatile chemicals. These five factors are the necessary conditions that the birth place of life must satisfy. Only the nuclear geyser can meet all five, in contrast to the previously proposed birth sites, such as tidal flat, submarine hydrothermal vent, and outer space. The nuclear reactor and associated geyser, which maintain the circulations of material and energy with its surrounding environment, are regarded as the nuclear geyser system that enables numerous kinds of chemical reactions to synthesize complex organic compounds, and where the most primitive metabolism could be generated.

  1. Steam turbine cycle

    International Nuclear Information System (INIS)

    Okuzumi, Naoaki.

    1994-01-01

    In a steam turbine cycle, steams exhausted from the turbine are extracted, and they are connected to a steam sucking pipe of a steam injector, and a discharge pipe of the steam injector is connected to an inlet of a water turbine. High pressure discharge water is obtained from low pressure steams by utilizing a pressurizing performance of the steam injector and the water turbine is rotated by the high pressure water to generate electric power. This recover and reutilize discharged heat of the steam turbine effectively, thereby enabling to improve heat efficiency of the steam turbine cycle. (T.M.)

  2. Numerical analysis and field study of time dependent exergy-energy of a gas-steam combined cycle

    Directory of Open Access Journals (Sweden)

    Barari Bamdad

    2012-01-01

    Full Text Available In this study, time dependent exergy analysis of the Fars Combined Power Plant Cycle has been investigated. Exergy analysis has been used for investigating each part of actual combined cycle by considering irreversibility from Apr 2006 to Oct 2010. Performance analysis has been done for each part by evaluating exergy destruction in each month. By using of exergy analysis, aging of each part has been evaluated respect to time duration. In addition, the rate of lost work for each month has been calculated and variation of this parameter has been considered as a function of aging rate. Finally, effects of exergy destruction of each part have been investigated on exergy destruction of whole cycle. Entire analysis has been done for Unit 3 and 4 of gas turbine cycle which combined by Unit B of steam cycle in Fars Combined Power Plant Cycle located in Fars province in Iran.

  3. MOSCAB. A geyser-concept bubble chamber to be used in a dark matter search

    Energy Technology Data Exchange (ETDEWEB)

    Antonicci, A.; Bertoni, R.; Mazza, R. [INFN, Sezione di Milano-Bicocca, Milan (Italy); Ardid, M. [Universitat Politecnica de Valencia Camino de Vera, Valencia (Spain); Bruno, G. [LNGS, INFN, Assergi (L' Aquila) (Italy); Burgio, N.; Santagata, A. [ENEA, Centro Ricerche Casaccia, Rome (Italy); Caruso, G.; Frullini, M.; Ricci, E. [Sapienza Universita di Roma, DIAEE, Rome (Italy); Cattaneo, D. [Universita di Milano-Bicocca, Dipt. di Informatica Sistemistica e Comunicazione, Milan (Italy); Chignoli, F.; Clemenza, M.; Lucchini, G.; Pullia, A.; Zanotti, L. [INFN, Sezione di Milano-Bicocca, Milan (Italy); Universita di Milano-Bicocca, Dipt. di Fisica, Milan (Italy); Corcione, M.; Quintino, A. [Sapienza Universita di Roma, DIAEE, Rome (Italy); INFN, Sezione di Roma La Sapienza, Rome (Italy); Cretara, L. [Sapienza Universita di Roma, DIAEE, Rome (Italy); Cundy, D. [Universita di Milano-Bicocca, Dipt. di Fisica, Milan (Italy); CERN, Geneva (Switzerland); Felis, I. [Universitat Politecnica de Valencia Camino de Vera, Valencia (Spain); Fulgione, W. [LNGS, INFN, Assergi (L' Aquila) (Italy); INAF, Osservatorio Astrofisico di Torino, Turin, Pino Torinese (Italy); Manara, L. [INFN, Sezione di Milano-Bicocca, Milan (Italy); Universita di Milano-Bicocca, Dipt. di Fisica, Milan (Italy); Maspero, M. [INFN, Sezione di Milano-Bicocca, Milan (Italy); Universita di Milano-Bicocca, DISAT, Milan (Italy); Papagni, A. [INFN, Sezione di Milano-Bicocca, Milan (Italy); Universita di Milano-Bicocca, Dipt. di Scienza dei Materiali, Milan (Italy); Perego, M. [INFN, Sezione di Milano-Bicocca, Milan (Italy); LNGS, INFN, Assergi (L' Aquila) (Italy); Podviyanuk, R. [LNGS, INFN, Assergi (L' Aquila) (Italy); Redaelli, N. [INFN, Sezione di Milano-Bicocca, Milan (Italy); Sorrenti, D. [INFN, Sezione di Milano-Bicocca, Milan (Italy); Universita di Milano-Bicocca, Dipt. di Informatica Sistemistica e Comunicazione, Milan (Italy); Collaboration: The MOSCAB Collaboration

    2017-11-15

    The MOSCAB experiment (Materia OSCura A Bolle) uses the ''geyser technique'', a variant of the superheated liquid technique of extreme simplicity. Operating principles of the new dark matter detector and technical solutions of the device are reported in detail. First results obtained in a series of test runs taken in laboratory demonstrate that we have successfully built and tested a geyser-concept bubble chamber that can be used in particle physics, especially in dark matter searches, and that we are ready to move underground for extensive data taking. (orig.)

  4. Anatomy of Old Faithful from subsurface seismic imaging of the Yellowstone Upper Geyser Basin

    KAUST Repository

    Wu, Sin-Mei

    2017-10-03

    The Upper Geyser Basin in Yellowstone National Park contains one of the highest concentrations of hydrothermal features on Earth including the iconic Old Faithful geyser. Although this system has been the focus of many geological, geochemical, and geophysical studies for decades, the shallow (<200 m) subsurface structure remains poorly characterized. To investigate the detailed subsurface geologic structure including the hydrothermal plumbing of the Upper Geyser Basin, we deployed an array of densely spaced three-component nodal seismographs in November of 2015. In this study, we extract Rayleigh-wave seismic signals between 1-10 Hz utilizing non-diffusive seismic waves excited by nearby active hydrothermal features with the following results. 1) imaging the shallow subsurface structure by utilizing stationary hydrothermal activity as a seismic source, 2) characterizing how local geologic conditions control the formation and location of the Old Faithful hydrothermal system, and 3) resolving a relatively shallow (10-60 m) and large reservoir located ~100 m southwest of Old Faithful geyser.

  5. Stress/strain changes and triggered seismicity at The Geysers, California

    Science.gov (United States)

    Gomberg, Joan; Davis, Scott

    1996-01-01

    The principal results of this study of remotely triggered seismicity in The Geysers geothermal field are the demonstration that triggering (initiation of earthquake failure) depends on a critical strain threshold and that the threshold level increases with decreasing frequency, or, equivalently, depends on strain rate. This threshold function derives from (1) analyses of dynamic strains associated with surface waves of the triggering earthquakes, (2) statistically measured aftershock zone dimensions, and (3) analytic functional representations of strains associated with power production and tides. The threshold is also consistent with triggering by static strain changes and implies that both static and dynamic strains may cause aftershocks. The observation that triggered seismicity probably occurs in addition to background activity also provides an important constraint on the triggering process. Assuming the physical processes underlying earthquake nucleation to be the same, Gomberg [this issue] discusses seismicity triggered by the MW 7.3 Landers earthquake, its constraints on the variability of triggering thresholds with site, and the implications of time delays between triggering and triggered earthquakes. Our results enable us to reject the hypothesis that dynamic strains simply nudge prestressed faults over a Coulomb failure threshold sooner than they would have otherwise. We interpret the rate-dependent triggering threshold as evidence of several competing processes with different time constants, the faster one(s) facilitating failure and the other(s) inhibiting it. Such competition is a common feature of theories of slip instability. All these results, not surprisingly, imply that to understand earthquake triggering one must consider not only simple failure criteria requiring exceedence of some constant threshold but also the requirements for generating instabilities.

  6. Stress/strain changes and triggered seismicity at The Geysers, California

    Science.gov (United States)

    Gomberg, J.; Davis, S.

    1996-01-01

    The principal results of this study of remotely triggered seismicity in The Geysers geothermal field are the demonstration that triggering (initiation of earthquake failure) depends on a critical strain threshold and that the threshold level increases with decreasing frequency or equivalently, depends on strain rate. This threshold function derives from (1) analyses of dynamic strains associated with surface waves of the triggering earthquakes, (2) statistically measured aftershock zone dimensions, and (3) analytic functional representations of strains associated with power production and tides. The threshold is also consistent with triggering by static strain changes and implies that both static and dynamic strains may cause aftershocks. The observation that triggered seismicity probably occurs in addition to background activity also provides an important constraint on the triggering process. Assuming the physical processes underlying earthquake nucleation to be the same, Gomberg [this issue] discusses seismicity triggered by the MW 7.3 Landers earthquake, its constraints on the variability of triggering thresholds with site, and the implications of time delays between triggering and triggered earthquakes. Our results enable us to reject the hypothesis that dynamic strains simply nudge prestressed faults over a Coulomb failure threshold sooner than they would have otherwise. We interpret the rate-dependent triggering threshold as evidence of several competing processes with different time constants, the faster one(s) facilitating failure and the other(s) inhibiting it. Such competition is a common feature of theories of slip instability. All these results, not surprisingly, imply that to understand earthquake triggering one must consider not only simple failure criteria requiring exceedence of some constant threshold but also the requirements for generating instabilities.

  7. Physical interpretation of geysering phenomena and periodic boiling instability at low flows

    International Nuclear Information System (INIS)

    Duffey, R.B.; Rohatgi, U.S.

    1996-01-01

    Over 30 years ago, Griffith showed that unstable and periodic initial boiling occurred in stagnant liquids in heated pipes coupled to a cooler or condensing plenum volume. This was called ''geysering'', and is a similar phenomenon to the rapid nucleation and voiding observed in tubes filled with superheated liquid. It is also called ''bumping'' when non-uniformly heated water or a chemical suddenly boils in laboratory glassware. In engineering, the stability and predictability has importance to the onset of bulk boiling in a natural and forced circulation loops. The latest available data show the observed stability and periodicity of the onset of boiling flow when there is a plenum, multiple heated channels, and a sustained subcooling in a circulating loop. We examine the available data, both old and new, and develop a new theory to illustrate the simple physics causing the observed periodicity of the flow. We examine the validity of the theory by comparison to all the geysering data, and develop a useful and simple correlation. We illustrate the equivalence of the onset of geysering to the onset of static instability in subcooled boiling. We also derive the stability boundary for geysering, utilizing turbulent transport analysis to determine the effects of pressure and other key parameters. This new result explains the greater stability region observed at higher pressures. The paper builds on the 30 years of quite independent thermal hydraulic work that is still fresh and useful today. We discuss the physical interpretation of geysering onset with a consistent theory, and show where refinements would be useful to the data correlations

  8. Numerical study of influences of crosswind and additional steam on the flow field and temperature of propane non-premixed turbulence flame

    Science.gov (United States)

    Wusnah; Bindar, Y.; Yunardi; Nur, F. M.; Syam, A. M.

    2018-03-01

    This paper presents results the process of combustion propane using computational fluid dynamics (CFD) to simulate the turbulent non-premixed flame under the influences of crosswinds and the ratio of fuel (propane) to steam, S. Configuration, discretization and boundary conditions of the flame are described using GambitTM software and integrated with FluentTM software for calculations of flow and reactive fields. This work focuses on the influence of various crosswind speeds (0–10 m/s) and values of S (0.14–2.35) while the velocity of fuel issued from the nozzle was kept constant at 20 m/s. A turbulence model, k-ɛ standard and combustion model, Eddy Dissipation model were employed for the calculation of velocity and temperature fields, respectively. The results are displayed in the form of predictive terrain profile of the propane flame at different crosswind speeds. The results of the propane flame profile demonstrated that the crosswind significantly affect the structure velocity and position of the flame which was off-center moving towards the direction of crosswind, eventually affect the temperature along the flame. As the values of S is increasing, the flame contour temperature decreases, until the flame was extinguished at S equals to 2.35. The combustion efficiency for a variety of crosswind speeds decreases with increasing values of S.

  9. Investigation of the mixed beta-photon radiation field in plant areas of the heat steam generator of the Obrigheim nuclear power station

    International Nuclear Information System (INIS)

    Burgkhardt, B.; Piesch, E.

    1988-10-01

    The investigations of the beta-photon radiation field in parts of the plant in the primary circuit were performed by irradiation experiments in different distances of exhausted disks of the heat steam generator using LiF-TLDs. The depth dose distribution for a detector free of mass is found on the basis of the measurement results by using a standardized extrapolation procedure. The measurement results show that the depth dose distribution is more or less independent of the detector-to-source distance if the absorption in air and the detector is taken into account. Thus low energy beta-photon fields can be analyzed, in general, using the results found in one distance of about 5 cm from the source. For the purpose of radiation protection at working places transmission factors for protective clothes and detectors of different thicknesses were determined. The estimation of the dose equivalents H'(0.07) and H'(10) and the dose equivalents in the lens of the eye and the testes shows that the low energy beta radiation component contributes only to the partial dose equivalent H'(0.07) and will be absorbed by a protective layer of 100 mg.cm -2 . (orig.) [de

  10. Steam Digest 2002

    Energy Technology Data Exchange (ETDEWEB)

    2003-11-01

    Steam Digest 2002 is a collection of articles published in the last year on steam system efficiency. DOE directly or indirectly facilitated the publication of the articles through it's BestPractices Steam effort. Steam Digest 2002 provides a variety of operational, design, marketing, and program and program assessment observations. Plant managers, engineers, and other plant operations personnel can refer to the information to improve industrial steam system management, efficiency, and performance.

  11. Isolation and Characterization of a Novel CO2-Tolerant Lactobacillus Strain from Crystal Geyser, UT

    Science.gov (United States)

    Santillan, E. U.; Major, J. R.; Omelon, C. R.; Shanahan, T. M.; Bennett, P.

    2013-12-01

    Capnophiles are microbes that grow in CO2 enriched environments. Cultured capnophiles generally, grow in 2 to 25% CO2, or 0.02 to 0.25 atm. When CO2 is sequestered in deep saline aquifers, the newly created high CO2 environment may select for capnophlic organisms. In this study, a capnophile was isolated from Crystal Geyser, a CO2 spring along the Little Grand Wash Fault, UT, a site being investigated as an analogue to CO2 sequestration. Crystal Geyser periodically erupts with CO2 charged water, indicating the presence of very high CO2 pressures below the subsurface, similar to sequestration conditions. Biomass was sampled by pumping springwater from approximately 10 m below the surface through filters. Filters were immediately placed in selective media within pressure vessels where they were pressurized to 10 atm in the field. Subsequent recultures produced an isolate, designated CG-1, that is most closely (99%) related to Lactobacillus casei on the strain level. CG-1 grows in tryptic soy broth, in PCO2 ranging from 0 atm to 10 atm, 40 times higher than pressures of previously cultured capnophiles. At 25 atm, growth is inhibited though survival can be as long as 5 days. At 50 atm, survival is poor, with sterilization occurring by 24 hours. Growth is optimal between pH values of 6 to 8, though sluggish if no CO2 is present. Its optimal salinity is 0.25 M NaCl though growth is observed ranging from 0 to 1 M NaCl. Growth is observed between 25o to 45o C, but optimal at 25oC. It consumes long-chained carbon molecules such as glucose, sucrose, and crude oil, and exhibits poor growth when supplied with lactate, acetate, formate, and pyruvate. The organism likely performs lactic acid fermentation as it requires no electron acceptors for growth and produces no acid, gas, and sulfide in triple sugar iron agar slants. CG-1 also expresses a variety of lipids, most notably cyclopropyl C19 (cycC19), or lactobacillic acid, characteristic of organisms belonging to the

  12. Steam saving during maintenance of the 50-MW Unit 7 at Los Azufres geothermal field, Michoacan; Ahorro de vapor durante el mantenimiento de la Unidad 7 de 50 MW en el campo geotermico de Los Azufres, Michoacan

    Energy Technology Data Exchange (ETDEWEB)

    Medina Barajas, Elvia Nohemi; Ruiz Lemus, Alejandro [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Residencia de Los Azufres, Morelia, Michoacan (Mexico)]. E-mail: elvia-medina@cfe.gob.mx

    2011-07-15

    Commercial-steam production in the southern area of Los Azufres, Mich., Mexico, Geothermal Field began in 1982 with the operation of Unit 2, the backpressure 5-MW unit, and continued in 1988 when the 50-MW condensing Unit 7 was commissioned. Today to supply steam to Unit 7, it is necessary to gather steam from 15 production wells, amounting 450 tons per hour (t/h) under operating conditions. During maintenance periods for Unit 7, production wells are removed from the steam-supply system but continue producing steam that is discharged to the atmosphere-a loss affecting the economic life of the geothermal reservoir. Therefore several actions have been proposed and tried to save the steam and preserve the geothermal resource. This paper presents the results of the actions and the technical and economic benefits obtained from them. [Spanish] La produccion de vapor con fines comerciales en la zona sur del campo geotermico de Los Azufres, Mich., Mexico, empezo en 1982 con la puesta en marcha de la Unidad 2 de 5 MW a contrapresion, para continuar en 1988 con la Unidad 7 de 50 MW a condensacion. Para cumplir con el suministro de vapor a la U-7, a la fecha es necesario integrar la produccion de 15 pozos productores, que producen un total de 450 toneladas por hora (t/h) a condiciones de operacion. Durante los periodos de mantenimiento de la U-7 los pozos son desintegrados del sistema de suministro, pero continuan produciendo vapor, el cual es descargado a la atmosfera sin ningun provecho, lo que representa una perdida que afecta la vida util del yacimiento geotermico. Por ello se han propuesto y aplicado diversas acciones operativas en cada uno de esos pozos con el objetivo de ahorrar vapor y preservar el recurso geotermico. En este trabajo se presentan los resultados de esas acciones y los beneficios tecnicos y economicos obtenidos.

  13. Steam turbine installations

    International Nuclear Information System (INIS)

    Bainbridge, A.

    1976-01-01

    The object of the arrangement described is to enable raising steam for driving steam turbines in a way suited to operating with liquid metals, such as Na, as heat transfer medium. A preheated water feed, in heat transfer relationship with the liquid metals, is passed through evaporator and superheater stages, and the superheated steam is supplied to the highest pressure stage of the steam turbine arrangement. Steam extracted intermediate the evaporator and superheater stages is employed to provide reheat for the lower pressure stage of the steam turbine. Only a major portion of the preheated water feed may be evaporated and this portion separated and supplied to the superheater stage. The feature of 'steam to steam' reheat avoids a second liquid metal heat transfer and hence represents a simplification. It also reduces the hazard associated with possible steam-liquid metal contact. (U.K.)

  14. Steam generator with perfected dryers

    International Nuclear Information System (INIS)

    Fenet, J.C.

    1987-01-01

    This steam generator has vertically superposed array of steam dryers. These dryers return the steam flow of 180 0 . The return of the water is made by draining channels to the steam production zone [fr

  15. Helium isotopes in geothermal systems: Iceland, The Geysers, Raft River and Steamboat Springs

    International Nuclear Information System (INIS)

    Torgersen, T.

    1982-01-01

    Helium isotope ratios have been measured in geothermal fluids from Iceland, The Geysers, Raft River, Steamboat Springs and Hawaii. These ratios have been interpreted in terms of the processes which supply He in distinct isotopic ratios and in terms of the processes which can alter the isotopic ratio. Using this interpretational scheme, Iceland is found to be an area of hot-spot magmatic He implying an active volcanic source although the data are suggestive of high-temperature weathering release of crustal He incorporated in the geothermal fluids. By comparison to fumarolic gases from Hawaii and Juan De Fuca and Cayman Trench basaltic glass samples, The Geysers contains MOR type magmatic He again implying an active volcanic source possibly a 'leaky' transform related to the San Andreas Fault System. Raft River contains only crustal He indicating no active volcanic sources. Steamboat Springs He isotope ratios are distinctly less than typical plate margin volcanics but must still have a magmatic source. (author)

  16. HTGR steam generator development

    International Nuclear Information System (INIS)

    Schuetzenduebel, W.G.; Hunt, P.S.; Weber, M.

    1976-01-01

    More than 40 gas-cooled reactor plants have produced in excess of 400 reactor years of operating experience which have proved a reasonably high rate of gas-cooled reactor steam generator availability. The steam generators used in these reactors include single U-tube and straight-tube steam generators as well as meander type and helically wound or involute tube steam generators. It appears that modern reactors are being equipped with helically wound steam generators of the once-through type as the end product of steam generator evolution in gas-cooled reactor plants. This paper provides a general overview of gas-cooled reactor steam generator evolution and operating experience and shows how design criteria and constraints, research and development, and experience data are factored into the design/development of modern helically wound tube steam generators for the present generation of gas-cooled reactors

  17. Steam Digest 2001

    Energy Technology Data Exchange (ETDEWEB)

    2002-01-01

    Steam Digest 2001 chronicles BestPractices Program's contributions to the industrial trade press for 2001, and presents articles that cover technical, financial and managerial aspects of steam optimization.

  18. Steam generator tube extraction

    International Nuclear Information System (INIS)

    Delorme, H.

    1985-05-01

    To enable tube examination on steam generators in service, Framatome has now developed a process for removing sections of steam generator tubes. Tube sections can be removed without being damaged for treating the tube section expanded in the tube sheet

  19. Steam sterilization does not require saturated steam

    NARCIS (Netherlands)

    van Doornmalen Gomez Hoyos, J. P.C.M.; Paunovic, A.; Kopinga, K.

    2017-01-01

    The most commonly applied method to sterilize re-usable medical devices in hospitals is steam sterilization. The essential conditions for steam sterilization are derived from sterilization in water. Microbiological experiments in aqueous solutions have been used to calculate various time–temperature

  20. OPTIMIZATION OF PATCHOULI OIL (POGOSTEMON CABLIN, BENTH WITH STEAM DISTILLATION ASSISTED BY PULSED ELECTRIC FIELD VIA RESPONSE SURFACE METHODOLOGY

    Directory of Open Access Journals (Sweden)

    SUKARDI

    2017-08-01

    Full Text Available The study was aimed to determine the role of pulsed electric field (PEF treatment before hydro-distillation of the patchouli oil. Response Surface Methodology (RSM was employed to optimize PEF treatment (voltages, frequencies and times of distillation of patchouli oil from dried patchouli crops. The experimental design and analysis the result to obtain the optimal processing parameters was a Box-Behnken Design (BBD. Three variables were examined in this study: voltages (1,000-2,000 volt; frequencies (1,000-2,000 Hz; and distillation time (4-8 hours. The results showed that the voltage greatly affects the volume of patchouli oil obtained and optimum condition of PEF was voltages of 2,000 volts, frequencies of 1,874 Hz, and 8 hours distillation. The patchouli oil obtained is 8.037 ml of 300 g of dry material (±2.7%. The verification of the model shows that 96.6% (7.76±0.15 ml can adequately for reflecting the expected optimization.

  1. The Invisibility of Steam

    Science.gov (United States)

    Greenslade, Thomas B., Jr.

    2014-01-01

    Almost everyone "knows" that steam is visible. After all, one can see the cloud of white issuing from the spout of a boiling tea kettle. In reality, steam is the gaseous phase of water and is invisible. What you see is light scattered from the tiny droplets of water that are the result of the condensation of the steam as its temperature…

  2. Strategies for steam

    International Nuclear Information System (INIS)

    Hennagir, T.

    1996-01-01

    This article is a review of worldwide developments in the steam turbine and heat recovery steam generator markets. The Far East is driving the market in HRSGs, while China is driving the market in orders placed for steam turbine prime movers. The efforts of several major suppliers are discussed, with brief technical details being provided for several projects

  3. Steam Digest: Volume IV

    Energy Technology Data Exchange (ETDEWEB)

    2004-07-01

    This edition of the Steam Digest is a compendium of 2003 articles on the technical and financial benefits of steam efficiency, presented by the stakeholders of the U.S. Department of Energy's BestPractices Steam effort.

  4. Steam Digest Volume IV

    Energy Technology Data Exchange (ETDEWEB)

    None

    2004-07-01

    This edition of the Steam Digest is a compendium of 2003 articles on the technical and financial benefits of steam efficiency, presented by the stakeholders of the U.S. Department of Energy's BestPractices Steam effort.

  5. Noise reduction in steam-vent points at the Cerro Prieto geothermal field, BC; Reduccion del ruido en puntos de desfogue en el campo geotermico de Cerro Prieto, BC

    Energy Technology Data Exchange (ETDEWEB)

    Miranda Herrera, Carlos A [Comision Federal de Electricidad, Residencia General de Cerro Prieto, Mexicali, B.C (Mexico)]. E-mail: carlos.miranda02@cfe.gob.mx

    2008-01-15

    Steam silencers have been placed on the power units regulation system of the Cerro Prieto geothermal field, but not where the steam-pipes vent high-pressure steam (rupture disks). Moreover, the power-unit silencers are large and their abilities to reduce noise depend on an external, uncontrollable factor: pores sizes in the volcanic rocks they are made of. Thus a compact, economic and relatively easy to construct metallic silencer was designed to be used at several points of dry-steam venting to minimize the noise. The design was based on orifice-plate equations and a prototype was constructed and tested. It proved capable of reducing noise by 30 decibels for atmospheric discharges of primary steam at operating pressures. The size of the silencer can be adjusted to the particular needs of each vent case. [Spanish] En el campo geotermico de Cerro Prieto solo existen silenciadores de vapor en el sistema de regulacion de las plantas generadoras, pero no en los sitios de desfogue de vapor a alta presion en los vaporductos (discos de ruptura). Ademas, los silenciadores de las plantas son muy robustos y su capacidad de reduccion del ruido depende de un factor externo no controlable, como es el tamano del poro de la roca volcanica con el que estan construidos. Por lo tanto, se diseno un silenciador metalico compacto, economico y relativamente facil de fabricar, para utilizarse en diversos puntos de descarga de vapor seco a fin de minimizar el ruido. El diseno se realizo con base en las ecuaciones de la placa de orificio. Se construyo un prototipo cuyas pruebas demostraron que es capaz de reducir el ruido hasta en 30 decibeles, al descargar desde la presion de operacion de vapor primario hacia la presion atmosferica. Las dimensiones del silenciador pueden ajustarse a las necesidades particulares de cada caso de desfogue.

  6. Steam generator tube rupture (SGTR) scenarios

    International Nuclear Information System (INIS)

    Auvinen, A.; Jokiniemi, J.K.; Laehde, A.; Routamo, T.; Lundstroem, P.; Tuomisto, H.; Dienstbier, J.; Guentay, S.; Suckow, D.; Dehbi, A.; Slootman, M.; Herranz, L.; Peyres, V.; Polo, J.

    2005-01-01

    The steam generator tube rupture (SGTR) scenarios project was carried out in the EU 5th framework programme in the field of nuclear safety during years 2000-2002. The first objective of the project was to generate a comprehensive database on fission product retention in a steam generator. The second objective was to verify and develop predictive models to support accident management interventions in steam generator tube rupture sequences, which either directly lead to severe accident conditions or are induced by other sequences leading to severe accidents. The models developed for fission product retention were to be included in severe accident codes. In addition, it was shown that existing models for turbulent deposition, which is the dominating deposition mechanism in dry conditions and at high flow rates, contain large uncertainties. The results of the project are applicable to various pressurised water reactors, including vertical steam generators (western PWR) and horizontal steam generators (VVER)

  7. Electricity from geothermal steam

    Energy Technology Data Exchange (ETDEWEB)

    Wheatcroft, E L.E.

    1959-01-01

    The development of the power station at Wairakei geothermal field is described. Wairakei is located at the center of New Zealand's volcanic belt, which lies within a major graben which is still undergoing some degree of downfaulting. A considerable number of wells, some exceeding 610 m, have been drilled. Steam and hot water are produced from both deep and shallow wells, which produce at gauge pressures of 1.5 MPa and 0.6 MPa, respectively. The turbines are fed by low, intermediate, and high pressure mains. The intermediate pressure turbine bank was installed as a replacement for a heavy water production facility which had originally been planned for the development. Stage 1 includes a 69 MW plant, and stage 2 will bring the capacity to 150 MW. A third stage, which would bring the output up to 250 MW had been proposed. The second stage involves the installation of more high pressure steam turbines, while the third stage would be powered primarily by hot water flashing. Generation is at 11 kV fed to a two-section 500 MVA board. Each section of the board feeds through a 40 MVA transformer to a pair of 220 V transmission lines which splice into the North Island grid. Other transformers feed 400 V auxiliaries and provide local supply.

  8. Steam generator materials

    International Nuclear Information System (INIS)

    Kim, Joung Soo; Han, J. H.; Kim, H. P.; Lim, Y. S.; Lee, D. H.; Suh, J. H.; Hwang, S. S.; Hur, D. H.; Kim, D. J.; Kim, Y. H.

    2002-05-01

    In order to keep the nuclear power plant(NPP)s safe and increase their operating efficiency, axial stress corrosion cracking(SCC)(IGA/IGSCC, PWSCC, PbSCC) test techniques were developed and SCC property data of the archive steam generator tubing materials having been used in nuclear power plants operating in Korea were produced. The data obtained in this study were data-based, which will be used to clarify the damage mechanisms, to operate the plants safely, and to increase the lifetime of the tubing. In addition, the basic technologies for the improvement of the SCC property of the tubing materials, for new SCC inhibition, for damaged tube repair, and for manufacturing processes of the tubing were developed. In the 1 phase of this long term research, basic SCC test data obtained from the archive steam generator tubing materials used in NPPs operating in Korea were established. These basic technologies developed in the 1 phase will be used in developing process optimization during the 2 phase in order to develop application technologies to the field nuclear power plants

  9. Cleanliness criteria to improve steam generator performance

    International Nuclear Information System (INIS)

    Schwarz, T.; Bouecke, R.; Odar, S.

    2005-01-01

    High steam generator performance is a prerequisite for high plant availability and possible life time extension. The major opponent to that is corrosion and fouling of the heating tubes. Such steam generator degradation problems arise from the continuous ingress of non-volatile contaminants, i.e. corrosion products and salt impurities may accumulate in the steam generators. These impurities have their origin in the secondary side systems. The corrosion products generally accumulate in the steam generators and form deposits not only in the flow restricted areas, such as on top of tube sheet and tube support structure, but also build scales on the steam generator heating tubes. In addition, the tube scales in general affect the steam generator thermal performance, which ultimately causes a reduction of power output. The most effective ways of counteracting all these degradation problems, and thus of improving the steam generator performance is to keep them in clean conditions or, if judged necessary, to plan cleaning measures such as mechanical tube sheet lancing or chemical cleaning. This paper presents a methodology how to assess the cleanliness condition of a steam generator by bringing together all available operational and inspection data such as thermal performance and water chemistry data. By means of this all-inclusive approach the cleanliness condition is quantified in terms of a fouling index. The fouling index allows to monitor the condition of a specific steam generator, compare it to other plants and, finally, to serve as criterion for cleaning measures such as chemical cleaning. The application of the cleanliness criteria and the achieved field results with respect to improvements of steam generator performance will be presented. (author)

  10. PWR steam generator tubing sample library

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    In order to compile the tubing sample library, two approaches were employed: (a) tubing sample replication by either chemical or mechanical means, based on field tube data and metallography reports for tubes already destructively examined; and (b) acquisition of field tubes removed from operating or retired steam generators. In addition, a unique mercury modeling concept is in use to guide the selection of replica samples. A compendium was compiled that summarizes field observations and morphologies of steam generator tube degradation types based on available NDE, destructive examinations, and field reports. This compendium was used in selecting candidate degradation types that were manufactured for inclusion in the tube library

  11. Minimal thermodynamic conditions in the reservoir to produce steam at the Cerro Prieto geothermal field, BC; Condiciones termodinamicas minimas del yacimiento para producir vapor en el campo geotermico de Cerro Prieto, B.C.

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Rodriguez; Marco Helio [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Residencia General de Cerro Prieto, Mexicali, Baja California (Mexico)]. E-mail: marco.rodriguez01@cfe.gob.mx

    2009-01-15

    Minimal thermodynamic conditions in the Cerro Prieto geothermal reservoir for steam production are defined, taking into account the minimal acceptable steam production at the surface, considering a rank of mixed-enthalpies for different well-depths, and allowing proper assessments for the impacts of the changes in fluid reservoir pressure and enthalpy. Factors able to influence steam production are discussed. They have to be considered when deciding whether or not to drill or repair a well in a particular area of the reservoir. These evaluations become much more relevant by considering the huge thermodynamic changes that have occurred at the Cerro Prieto geothermal reservoir from its development, starting in 1973, which has lead to abandoning some steam producing areas in the field. [Spanish] Las condiciones termodinamicas minimas del yacimiento geotermico de Cerro Prieto, BC, para producir vapor se determinan tomando en cuenta la minima produccion de vapor aceptable en superficie, considerando un rango de entalpias de la mezcla y para diferentes profundidades de pozos, lo que permite valorar adecuadamente el impacto de la evolucion de la presion y entalpia del fluido en el yacimiento. Se discuten los factores que pueden afectar la produccion de vapor, los cuales se deben tomar en cuenta para determinar la conveniencia o no de perforar o reparar un pozo en determinada zona del yacimiento. Estas evaluaciones adquieren gran relevancia al considerar los enormes cambios termodinamicos que ha presentado el yacimiento geotermico de Cerro Prieto, como resultado de su explotacion iniciada en 1973, lo que ha llevado a abandonar algunas zonas del campo para la produccion de vapor. Palabras Clave: Cerro Prieto, entalpia, evaluacion de yacimientos, politicas de explotacion, presion, produccion de vapor.

  12. Condensation of steam

    International Nuclear Information System (INIS)

    Prisyazhniuk, V.A.

    2002-01-01

    An equation for nucleation kinetics in steam condensation has been derived, the equation taking into account the concurrent and independent functioning of two nucleation mechanisms: the homogeneous one and the heterogeneous one. The equation is a most general-purpose one and includes all the previously known condensation models as special cases. It is shown how the equation can be used in analyzing the process of steam condensation in the condenser of an industrial steam-turbine plant, and in working out new ways of raising the efficiency of the condenser, as well as of the steam-turbine plant as a whole. (orig.)

  13. EPRI steam generator programs

    International Nuclear Information System (INIS)

    Martel, L.J.; Passell, T.O.; Bryant, P.E.C.; Rentler, R.M.

    1977-01-01

    The paper describes the current overall EPRI steam generator program plan and some of the ongoing projects. Because of the recent occurrence of a corrosion phenomenon called ''denting,'' which has affected a number of operating utilities, an expanded program plan is being developed which addresses the broad and urgent needs required to achieve improved steam generator reliability. The goal of improved steam generator reliability will require advances in various technologies and also a management philosophy that encourages conscientious efforts to apply the improved technologies to the design, procurement, and operation of plant systems and components that affect the full life reliability of steam generators

  14. Real-time Remote Data Online For Norris Geyser Basin in Yellowstone National Park

    Science.gov (United States)

    Perry, J. E.; Lowenstern, J. B.; Clor, L.; Cervelli, P. F.; Allen, S. T.; Heasler, H.; Moloney, T.

    2010-12-01

    Perry, John, Lowenstern, Jacob, Cervelli, Peter, Clor, Laura, Heasler, Henry, Allen, Scott, Moloney, Tim During June 2010, ten 900MHz wireless temperature data loggers (nodes) were installed around the Norris Geyser Basin to monitor geothermal features, streams and soil temperatures. The loggers can provide near real-time updates on temperature variations within 0.2 deg C due to hydrothermal discharges or subsurface fluid migration. Each sensor node is programmed to measure the temperature every two minutes and automatically upload data to the base station computer daily. The hardware consists of a waterproof case containing an M5 logger (made by Marathon Products, Inc.®) with internal memory, lithium D-cell batteries and a 900 MHz, 1-W-transceiver and 5 meter long Teflon-coated probe with a thermistor sensor. Tethered stub or panel antennas are oriented to optimize signal strength to the base station near the Norris Museum. A 0.61 meter-long base-station antenna located 10m high provides signal to the furthest node over 850 meters away with most being “line-of-sight”. A 20-meter coaxial cable and lightning grounding wire connects the base-station antenna to an Ethernet-radio connected to the YNP local-area network. A server located 26-km north at Mammoth Hot Springs requests data at regular intervals (normally daily), archives the information, and then sends it to the USGS for further archiving and internet distribution. During periods of unusual hydrothermal behavior, data can be requested as needed, and it is possible to set user-programmable alarm limits for notification. The RF network is designed to monitor changes from three different sub-basins at Norris (Gray Lakes, Steamboat-Echinus and Porcelain Basin), the main Tantalus Creek drainage, and five individual thermal features (Constant, Porkchop, Steamboat and Echinus Geysers, and Opalescent Spring). The logger installed in Nuphar Lake provides ambient temperatures controlled solely by local

  15. Geothermal energy and the land resource: conflicts and constraints in The Geysers-Calistoga KGRA

    Energy Technology Data Exchange (ETDEWEB)

    O' Banion, K.; Hall, C.

    1980-07-14

    This study of potential land-related impacts of geothermal power development in The Geysers region focuses on Lake County because it has most of the undeveloped resource and the least regulatory capability. First, the land resource is characterized in terms of its ecological, hydrological, agricultural, and recreational value; intrinsic natural hazards; and the adequacy of roads and utility systems. Based on those factors, the potential land-use conflicts and constraints that geothermal development may encounter in the region are identified and the availability and relative suitability of land for such development is determined. A brief review of laws and powers germane to geothermal land-use regulation is included.

  16. Land-use conflicts in The Geysers-Calistoga KGRA: a preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    O' Banion, K.; Hall, C.; Haven, K.

    1979-12-01

    This preliminary study of potential land use conflicts of geothermal development in The Geysers region, one component of the LLL/LBL socioeconomic program, focuses on Lake County because it has most of the undeveloped resource and the least regulatory capability. The land resource is characterized in terms of its ecological, hydrological, agricultural, and recreational value; intrinsic natural hazards; and the adequacy of roads and utility systems and each factor is depicted on a map. Then those factors are analyzed for potential conflicts with both geothermal and urban development and the conflicts displayed on respective maps. A brief review of laws and methods germane to geothermal land-use regulation is included.

  17. Seismicity at Old Faithful Geyser: an isolated source of geothermal noise and possible analogue of volcanic seismicity

    Science.gov (United States)

    Kieffer, Susan Werner

    1984-09-01

    Old Faithful Geyser in Yellowstone National Park, U.S.A., is a relatively isolated source of seismic noise and exhibits seismic behavior similar to that observed at many volcanoes, including "bubblequakes" that resemble B-type "earthquakes", harmonic tremor before and during eruptions, and periods of seismic quiet prior to eruptions. Although Old Faithful differs from volcanoes in that the conduit is continuously open, that rock-fracturing is not a process responsible for seismicity, and that the erupting fluid is inviscid H 2O rather than viscous magma, there are also remarkable similarities in the problems of heat and mass recharge to the system, in the eruption dynamics, and in the seismicity. Water rises irregularly into the immediate reservoir of Old Faithful as recharge occurs, a fact that suggests that there are two enlarged storage regions: one between 18 and 22 m (the base of the immediate reservoir) and one between about 10 and 12 m depth. Transport of heat from hot water or steam entering at the base of the recharging water column into cooler overlying water occurs by migration of steam bubbles upward and their collapse in the cooler water, and by episodes of convective overturn. An eruption occurs when the temperature of the near-surface water exceeds the boiling point if the entire water column is sufficiently close to the boiling curve that the propagation of pressure-release waves (rarefactions) down the column can bring the liquid water onto the boiling curve. The process of conversion of the liquid water in the conduit at the onset of an eruption into a two-phase liquid-vapor mixture takes on the order of 30 s. The seismicity is directly related to the sequence of filling and heating during the recharge cycle, and to the fluid mechanics of the eruption. Short (0.2-0.3 s), monochromatic, high-frequency events (20-60 Hz) resembling unsustained harmonic tremor and, in some instances, B-type volcanic earthquakes, occur when exploding or imploding

  18. STEAM by Design

    Science.gov (United States)

    Keane, Linda; Keane, Mark

    2016-01-01

    We live in a designed world. STEAM by Design presents a transdisciplinary approach to learning that challenges young minds with the task of making a better world. Learning today, like life, is dynamic, connected and engaging. STEAM (Science, Technology, Environment, Engineering, Art, and Math) teaching and learning integrates information in…

  19. Steampunk: Full Steam Ahead

    Science.gov (United States)

    Campbell, Heather M.

    2010-01-01

    Steam-powered machines, anachronistic technology, clockwork automatons, gas-filled airships, tentacled monsters, fob watches, and top hats--these are all elements of steampunk. Steampunk is both speculative fiction that imagines technology evolved from steam-powered cogs and gears--instead of from electricity and computers--and a movement that…

  20. Safety Picks up "STEAM"

    Science.gov (United States)

    Roy, Ken

    2016-01-01

    This column shares safety information for the classroom. STEAM subjects--science, technology, engineering, art, and mathematics--are essential for fostering students' 21st-century skills. STEAM promotes critical-thinking skills, including analysis, assessment, categorization, classification, interpretation, justification, and prediction, and are…

  1. Steam-water separator

    International Nuclear Information System (INIS)

    Modrak, T.M.; Curtis, R.W.

    1978-01-01

    A two-stage steam-water separating device is introduced, where the second stage is made as a cyclone separator. The water separated here is collected in the first stage of the inner tube and is returned to the steam raising unit. (TK) [de

  2. Steam power plant

    International Nuclear Information System (INIS)

    Campbell, J.W.E.

    1981-01-01

    This invention relates to power plant forced flow boilers operating with water letdown. The letdown water is arranged to deliver heat to partly expanded steam passing through a steam reheater connected between two stages of the prime mover. (U.K.)

  3. An Isothermal Steam Expander for an Industrial Steam Supplying System

    Directory of Open Access Journals (Sweden)

    Chen-Kuang Lin

    2015-01-01

    Full Text Available Steam is an essential medium used in the industrial process. To ensure steam quality, small and middle scale boilers are often adopted. However, because a higher steam pressure (compared to the necessary steam pressure is generated, the boiler’s steam pressure will be reduced via a pressure regulator before the steam is directed through the process. Unfortunately, pressure is somewhat wasted during the reducing process. Therefore, in order to promote energy efficiency, a pressure regulator is replaced by a steam expander. With this steam expander, the pressure will be transformed into mechanical energy and extracted during the expansion process. A new type of isothermal steam expander for an industrial steam supplying system will be presented in the paper. The isothermal steam expander will improve the energy efficiency of a traditional steam expander by replacing the isentropic process with an isothermal expansion process. With this, steam condensation will decrease, energy will increase, and steam quality will be improved. Moreover, the mathematical model of the isothermal steam expander will be established by using the Schmidt theory, the same principle used to analyze Stirling engines. Consequently, by verifying the correctness of the theoretical model for the isothermal steam expander using experimental data, a prototype of 100 c.c. isothermal steam expander is constructed.

  4. Steam generator life management

    International Nuclear Information System (INIS)

    Tapping, R.L.; Nickerson, J.; Spekkens, P.; Maruska, C.

    1998-01-01

    Steam generators are a critical component of a nuclear power reactor, and can contribute significantly to station unavailability, as has been amply demonstrated in Pressurized Water Reactors (PWRs). CANDU steam generators are not immune to steam generator degradation, and the variety of CANDU steam generator designs and tube materials has led to some unexpected challenges. However, aggressive remedial actions, and careful proactive maintenance activities, have led to a decrease in steam generator-related station unavailability of Canadian CANDUs. AECL and the CANDU utilities have defined programs that will enable existing or new steam generators to operate effectively for 40 years. Research and development work covers corrosion and mechanical degradation of tube bundles and internals, chemistry, thermal hydraulics, fouling, inspection and cleaning, as well as provision for specially tool development for specific problem solving. A major driving force is development of CANDU-specific fitness-for-service guidelines, including appropriate inspection and monitoring technology to measure steam generator condition. Longer-range work focuses on development of intelligent on-line monitoring for the feedwater system and steam generator. New designs have reduced risk of corrosion and fouling, are more easily inspected and cleaned, and are less susceptible to mechanical damage. The Canadian CANDU utilities have developed programs for remedial actions to combat degradation of performance (Gentilly-2, Point Lepreau, Bruce A/B, Pickering A/B), and have developed strategic plans to ensure that good future operation is ensured. This report shows how recent advances in cleaning technology are integrated into a life management strategy, discusses downcomer flow measurement as a means of monitoring steam generator condition, and describes recent advances in hideout return as a life management tool. The research and development program, as well as operating experience, has identified

  5. GEYSERS: a novel architecture for virtualization and co-provisioning of dynamic optical networks and IT services

    NARCIS (Netherlands)

    Escalona, E.; Peng, S.; Nejabati, R.; Simeonidou, D.; García-Espín, J.A.; Ferrer, J.; Figuerola, S.; Landi, G.; Ciulli, N.; Jiménez, J.; Belter, B.; Demchenko, Y.; de Laat, C.; Chen, X.; Yukan, A.; Soudan, S.; Vicat-Blanc, P.; Buysse, J.; de Leenheer, M.; Develder, C.; Tzanakaki, A.; Robinson, P.; Brogle, M.; Bohnert, T.M.

    2011-01-01

    GEYSERS aims at defining an end-to-end network architecture that offers a novel planning, provisioning and operational framework for optical network and IT infrastructure providers and operators. In this framework, physical infrastructure resources (network and IT) are dynamically partitioned to

  6. How the geysers, tidal stresses, and thermal emission across the south polar terrain of enceladus are related

    International Nuclear Information System (INIS)

    Porco, Carolyn; DiNino, Daiana; Nimmo, Francis

    2014-01-01

    We present the first comprehensive examination of the geysering, tidal stresses, and anomalous thermal emission across the south pole of Enceladus and discuss the implications for the moon's thermal history and interior structure. A 6.5 yr survey of the moon's south polar terrain (SPT) by the Cassini imaging experiment has located ∼100 jets or geysers erupting from four prominent fractures crossing the region. Comparing these results with predictions of diurnally varying tidal stresses and with Cassini low resolution thermal maps shows that all three phenomena are spatially correlated. The coincidence of individual jets with very small (∼10 m) hot spots detected in high resolution Cassini VIMS data strongly suggests that the heat accompanying the geysers is not produced by shearing in the upper brittle layer but rather is transported, in the form of latent heat, from a sub-ice-shell sea of liquid water, with vapor condensing on the near-surface walls of the fractures. Normal stresses modulate the geysering activity, as shown in the accompanying paper; we demonstrate here they are capable of opening water-filled cracks all the way down to the sea. If Enceladus' eccentricity and heat production are in steady state today, the currently erupting material and anomalous heat must have been produced in an earlier epoch. If regional tidal heating is occurring today, it may be responsible for some of the erupting water and heat. Future Cassini observations may settle the question.

  7. Steam generator tube failures

    International Nuclear Information System (INIS)

    MacDonald, P.E.; Shah, V.N.; Ward, L.W.; Ellison, P.G.

    1996-04-01

    A review and summary of the available information on steam generator tubing failures and the impact of these failures on plant safety is presented. The following topics are covered: pressurized water reactor (PWR), Canadian deuterium uranium (CANDU) reactor, and Russian water moderated, water cooled energy reactor (VVER) steam generator degradation, PWR steam generator tube ruptures, the thermal-hydraulic response of a PWR plant with a faulted steam generator, the risk significance of steam generator tube rupture accidents, tubing inspection requirements and fitness-for-service criteria in various countries, and defect detection reliability and sizing accuracy. A significant number of steam generator tubes are defective and are removed from service or repaired each year. This wide spread damage has been caused by many diverse degradation mechanisms, some of which are difficult to detect and predict. In addition, spontaneous tube ruptures have occurred at the rate of about one every 2 years over the last 20 years, and incipient tube ruptures (tube failures usually identified with leak detection monitors just before rupture) have been occurring at the rate of about one per year. These ruptures have caused complex plant transients which have not always been easy for the reactor operators to control. Our analysis shows that if more than 15 tubes rupture during a main steam line break, the system response could lead to core melting. Although spontaneous and induced steam generator tube ruptures are small contributors to the total core damage frequency calculated in probabilistic risk assessments, they are risk significant because the radionuclides are likely to bypass the reactor containment building. The frequency of steam generator tube ruptures can be significantly reduced through appropriate and timely inspections and repairs or removal from service

  8. An integrated methodology for sub-surface fracture characterization using microseismic data: A case study at the NW Geysers

    Science.gov (United States)

    Aminzadeh, Fred; Tafti, Tayeb A.; Maity, Debotyam

    2013-04-01

    Geothermal and unconventional hydrocarbon reservoirs are often characterized by low permeability and porosity. So, they are difficult to produce and require stimulation techniques, such as thermal shear deactivation and hydraulic fracturing. Fractures provide porosity for fluid storage and permeability for fluid movement and play an important role in production from this kind of reservoirs. Hence, characterization of fractures has become a vitally important consideration in every aspect of exploration, development and production so as to provide additional energy resources for the world. During the injection or production of fluid, induced seismicity (micro-seismic events) can be caused by reactivated shears created fractures or the natural fractures in shear zones and faults. Monitoring these events can help visualize fracture growth during injection stimulation. Although the locations of microseismic events can be a useful characterization tool and have been used by many authors, we go beyond these locations to characterize fractures more reliably. Tomographic inversion, fuzzy clustering, and shear wave splitting are three methods that can be applied to microseismic data to obtain reliable characteristics about fractured areas. In this article, we show how each method can help us in the characterization process. In addition, we demonstrate how they can be integrated with each other or with other data for a more holistic approach. The knowledge gained might be used to optimize drilling targets or stimulation jobs to reduce costs and maximize production. Some of the concepts discussed in this paper are general in nature, and may be more applicable to unconventional hydrocarbon reservoirs than the metamorphic and igneous reservoir rocks at The Geysers geothermal field.

  9. Monte Carlo study of MOSFET dosimeter dose correction factors considering energy spectrum of radiation field in a steam generator channel head

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Sung Koo; Choi, Sang Hyoun; Kim, Chan Hyeong [Hanyang Univ., Seoul (Korea, Republic of)

    2006-12-15

    In Korea, a real-time effective dose measurement system is in development. The system uses 32 high-sensitivity MOSFET dosimeters to measure radiation doses at various organ locations in an anthropomorphic physical phantom. The MOSFET dosimeters are, however, mainly made of silicon and shows some degree of energy and angular dependence especially for low energy photons. This study determines the correction factors to correct for these dependences of the MOSFET dosimeters for accurate measurement of radiation doses at organ locations in the phantom. For this, first, the dose correction factors of MOSFET dosimeters were determined for the energy spectrum in the steam generator channel of the Kori Nuclear Power Plant Unit no.1 by Monte Carlo simulations. Then, the results were compared with the dose correction factors from 0.662 MeV and 1.25 MeV mono-energetic photons. The difference of the dose correction factors were found very negligible ({<=}1.5%), which in general shows that the dose corrections factors determined from 0.662 MeV and 1.25 MeV can be in a steam general channel head of a nuclear power plant. The measured effective dose was generally found to decrease by {approx}7% when we apply the dose correction factors.

  10. A three-dimensional laboratory steam injection model allowing in situ saturation measurements. [Comparing steam injection and steam foam injection with nitrogen and without nitrogen

    Energy Technology Data Exchange (ETDEWEB)

    Demiral, B.M.R.; Pettit, P.A.; Castanier, L.M.; Brigham, W.E.

    1992-08-01

    The CT imaging technique together with temperature and pressure measurements were used to follow the steam propagation during steam and steam foam injection experiments in a three dimensional laboratory steam injection model. The advantages and disadvantages of different geometries were examined to find out which could best represent radial and gravity override flows and also fit the dimensions of the scanning field of the CT scanner. During experiments, steam was injected continuously at a constant rate into the water saturated model and CT scans were taken at six different cross sections of the model. Pressure and temperature data were collected with time at three different levels in the model. During steam injection experiments, the saturations obtained by CT matched well with the temperature data. That is, the steam override as observed by temperature data was also clearly seen on the CT pictures. During the runs where foam was present, the saturation distributions obtained from CT pictures showed a piston like displacement. However, the temperature distributions were different depending on the type of steam foam process used. The results clearly show that the pressure/temperature data alone are not sufficient to study steam foam in the presence of non-condensible gas.

  11. Parametric Optimization of Biomass Steam-and-Gas Plant

    Directory of Open Access Journals (Sweden)

    V. Sednin

    2013-01-01

    Full Text Available The paper contains a parametric analysis of the simplest scheme of a steam-and gas plant for the conditions required for biomass burning. It has been shown that application of gas-turbine and steam-and-gas plants can significantly exceed an efficiency of steam-power supply units which are used at the present moment. Optimum thermo-dynamical conditions for application of steam-and gas plants with the purpose to burn biomass require new technological solutions in the field of heat-exchange equipment designs.

  12. Determination of heat losses in the Cerro Prieto, Baja California, geothermal field steam transportation network based on the thermal insulation condition of the steam pipelines; Determinacion de perdidas de calor en la red de transporte de vapor del campo geotermico de Cerro Prieto, Baja California, con base en el estado fisico del aislamiento termico de vaporductos

    Energy Technology Data Exchange (ETDEWEB)

    Ovando Castelar, Rosember; Garcia Gutierrez, Alfonso; Martinez Estrella, Juan Ignacio [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: rovando@iie.org.mx; Canchola Felix, Ismael; Jacobo Galvan, Paul; Miranda Herrera, Carlos; Mora Perez, Othon [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Residencia General de Cerro Prieto, Mexicali, B.C. (Mexico)

    2011-07-15

    In Cerro Prieto Geothermal Field (CPGF), the steam from producing wells is transported to power plants through a large and complex system of pipes thermally insulated with a 2 inches thick mineral wool or a fiber glass layer and an external aluminum or iron cover. The insulation material has been exposed to weather conditions during the field operation and has suffered density and thickness changes. In some cases the insulation has been lost completely, increasing heat transfer from the pipes to the environment. This paper analyzes the impact of the conditions of thermal insulation on heat losses in the CPGF steam-pipeline network. The heat losses are calculated by applying an iterative method to determine the surface temperature based on a heat balance calculated from the three basic mechanisms of heat transfer: conduction, convection, and radiation. Finally, using length and diameter data corresponding to the condition of the thermal insulation of each pipeline-and field operation data, the overall heat losses are quantified for steam lines throughout the pipeline network in the field. The results allow us to evaluate the magnitude of the heat losses in comparison with the overall energy losses occurring during steam transport from wells to the power plants. [Spanish] En el Campo Geotermico de Cerro Prieto (CGCP), BC, el transporte de vapor desde los pozos hasta las plantas generadoras de electricidad se lleva a cabo mediante un extenso y complejo sistema de tuberias que tipicamente se encuentran aisladas termicamente con una capa de 2 pulgadas de material aislante a base de lana mineral o fibra de vidrio, y una proteccion mecanica de aluminio o hierro galvanizado. Debido a la exposicion a las condiciones meteorologicas a traves del tiempo de operacion del campo, el aislamiento ha experimentado cambios en su densidad y espesor y en ocasiones se ha perdido por completo, lo cual repercute en una mayor transferencia de calor de las tuberias hacia el medio ambiente

  13. The Time Variability of Individual Geysers in the Plume of Enceladus

    Science.gov (United States)

    Trumbo, S. K.; Ewald, S. P.; Ingersoll, A. P.

    2016-12-01

    Porco et al. (2014) [1] published the locations of 100 jets along the so-called "tiger stripes" that feed the massive plume of Enceladus. Hedman et al. (2013) [2] observed fluctuations in integrated plume brightness in response to periodic tidal forcing on the orbital timescale of Enceladus, in which the plume is brightest near apocenter and dimmest near pericenter. The thin crack models of Hurford et al. (2007, 2012) [3, 4] suggest that individual jets should respond to the same forces on similar timescales. However, if the jets are produced via vapor and liquid propagation through thin subterranean cracks, then they may also be controlled thermodynamically and dependent on the timescale of ice buildup on the conduit walls. Ingersoll and Ewald (2016) [5] demonstrate that the plume also varies on decadal timescales, perhaps as a result of an eleven-year tide or long-term ice accumulation within source cracks. We examine Cassini ISS Narrow Angle Camera images spanning 2005 - 2012 in order to assess the temporal variability of individual geysers and regional emission in the plume. We observe both the appearance and disappearance of individual jets, as well as visible changes in regional emission. Our observations suggest localized variations on timescales of months to years that are not easily tied to mean anomaly, but that may be indicative of subsurface processes. Theoretical models of the geyser mechanisms and subsurface plumbing predict closure timescales of individual cracks that are dependent on model parameters, such as crack width, crack tortuosity, and water table depth [6, 7, 8]. Thus, we discuss possible implications of these observations for both the mechanism and anatomy of an Enceladus geyser. [1] Porco et al. (2014), AJ, 148, 3. [2] Hedman et al. (2013), Nature, 500, 182 - 184. [3] Hurford et al. (2007), Nature, 447, 292 - 294. [4] Hurford et al. (2012), Icarus, 220, 896 - 903. [5] Ingersoll and Ewald (2016), Icarus, in review. [6] Ingersoll and

  14. French steam generator

    International Nuclear Information System (INIS)

    Remond, A.

    1986-01-01

    After recalling the potential damage mode of tubes of steam generator, the author recalls the safety criteria used in France. The improvements and the process of damage prejudice and reparation for tubular bundle are presented [fr

  15. Steam purity in PWRs

    International Nuclear Information System (INIS)

    Hopkinson, J.

    1982-01-01

    Impurities enter the secondary loop of the PWR through both makeup water from lake or well and cooling-water leaks in the condenser. These impurities can be carried to the steam generator, where they cause corrosion deposits to form. Corrosion products in steam are swept further through the system and become concentrated at the point in the low-pressure turbine where steam begins to condense. Several plants have effectively reduced impurities, and therefore corrosion, by installing a demineralizer for the makeup water, a resin-bed system to clean condensed steam from the condenser, and a deaerator to remove oxygen from the water and so lower the risk of system metal oxidation. 5 references, 1 figure

  16. Liquid metal steam generator

    International Nuclear Information System (INIS)

    Wolowodiuk, W.

    1975-01-01

    A liquid metal heated steam generator is described which in the event of a tube failure quickly exhausts out of the steam generator the products of the reaction between the water and the liquid metal. The steam is generated in a plurality of bayonet tubes which are heated by liquid metal flowing over them between an inner cylinder and an outer cylinder. The inner cylinder extends above the level of liquid metal but below the main tube sheet. A central pipe extends down into the inner cylinder with a centrifugal separator between it and the inner cylinder at its lower end and an involute deflector plate above the separator so that the products of a reaction between the liquid metal and the water will be deflected downwardly by the deflector plate and through the separator so that the liquid metal will flow outwardly and away from the central pipe through which the steam and gaseous reaction products are exhausted. (U.S.)

  17. Steam cleaning device

    International Nuclear Information System (INIS)

    Karaki, Mikio; Muraoka, Shoichi.

    1985-01-01

    Purpose: To clean complicated and long objects to be cleaned having a structure like that of nuclear reactor fuel assembly. Constitution: Steams are blown from the bottom of a fuel assembly and soon condensated initially at the bottom of a vertical water tank due to water filled therein. Then, since water in the tank is warmed nearly to the saturation temperature, purified water is supplied from a injection device below to the injection device above the water tank on every device. In this way, since purified water is sprayed successively from below to above and steams are condensated in each of the places, the entire fuel assembly elongated in the vertical direction can be cleaned completely. Water in the reservoir goes upward like the steam flow and is drained together with the eliminated contaminations through an overflow pipe. After the cleaning has been completed, a main steam valve is closed and the drain valve is opened to drain water. (Kawakami, Y.)

  18. Steam generator water lancing

    International Nuclear Information System (INIS)

    Kamler, F.; Schneider, W.

    1992-01-01

    The tubesheet and tube support plate deposits in CANDU steam generators are notable for their hardness. Also notable is the wide variety of steam generator access situations. Because of the sludge hardness and the difficulty of the access, traditional water lancing processes which directed jets from the central tube free lane or from the periphery of the bundle have proven unsuitable. This has led to the need for some very unique inter tube water lancing devices which could direct powerful water jets directly onto the deposits. This type of process was applied to the upper broached plates of the Bruce A steam generators, which had become severely blocked. It has since been applied to various other steam generator situations. This paper describes the flexlance equipment development, qualification, and performance in the various CANDU applications. 4 refs., 2 tabs., 7 figs

  19. Steam-water separator

    International Nuclear Information System (INIS)

    Modrak, T.M.; Curtis, R.W.

    1978-01-01

    The steam-water separator connected downstream of a steam generator consists of a vertical centrifugal separator with swirl blades between two concentric pipes and a cyclone separator located above. The water separated in the cyclone separator is collected in the inner tube of the centrifugal separator which is closed at the bottom. This design allows the overall height of the separator to be reduced. (DG) [de

  20. Hydraulic model of the steam-lines network of the Cerro Prieto, B.C., geothermal field; Modelo hidraulico de la red de vaporductos del campo geotermico de Cerro Prieto, B.C.

    Energy Technology Data Exchange (ETDEWEB)

    Salaices, E; Garcia, A; Martinez J I; Ovando, R; Cecenas, M; Hernandez A F [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: salaices@iie.org.mx; Canchola, I; Mora, O; Miranda, C; Herandez, M; Lopez, S; Murillo, I [Comision Federal de Electricidad, B.C (Mexico)

    2007-01-15

    The steam-line network of the Cerro Prieto geothermal field is composed of 184 wells, and 162 of the wells are integrated and connected by pipes. Thirteen power units, with an installed electrical capacity of 720 MW, are fed by that network. The network length is 120 km, including pipes of several diameters with branches and interconnections. The extension and complexity of the steam-line system make it difficult to analyze the transport and supply of steam to the power plants. For that it was necessary to have a tool capable of analyzing the system and the performance of the network as a whole, as well as the direction and flow volumes in each part of the system. In this paper, a hydraulic model of the Cerro Prieto steam-line network is presented. The model can determine the performance of the whole network by quantifying the pressure drops, flows and heat losses of the components. The model analyses the consequences of changes in operating conditions, steam production, maintenance activities and design (such as the integration of new wells). The model was developed using PIPEPHASE 9.0, a numeric simulator of multi-phase flow in steady state with heat transfer. It is used to model systems and pipe networks for steam- and condensate-transport. [Spanish] La red de vaporductos del campo geotermico de Cerro Prieto esta compuesta por un conjunto de 184 pozos, de los cuales 162 son pozos integrados, interconectados entre si a traves de una red de tuberias. Por medio de esta red se alimentan 13 unidades generadoras de electricidad con una capacidad total instalada de 720 MWe. La red tiene una longitud aproximada de 120 kilometros y esta compuesta por tuberias de diferentes diametros, ramales, interconexiones, etc. La complejidad y extension del sistema de vaporductos hace muy dificil el analisis del transporte y suministro de vapor a las plantas generadoras. Lo anterior creo la necesidad de contar con una herramienta que ayudara en el analisis del sistema con el fin de

  1. Steam injection for heavy oil recovery: Modeling of wellbore heat efficiency and analysis of steam injection performance

    International Nuclear Information System (INIS)

    Gu, Hao; Cheng, Linsong; Huang, Shijun; Li, Bokai; Shen, Fei; Fang, Wenchao; Hu, Changhao

    2015-01-01

    Highlights: • A comprehensive mathematical model was established to estimate wellbore heat efficiency of steam injection wells. • A simplified approach of predicting steam pressure in wellbores was proposed. • High wellhead injection rate and wellhead steam quality can improve wellbore heat efficiency. • High wellbore heat efficiency does not necessarily mean good performance of heavy oil recovery. • Using excellent insulation materials is a good way to save water and fuels. - Abstract: The aims of this work are to present a comprehensive mathematical model for estimating wellbore heat efficiency and to analyze performance of steam injection for heavy oil recovery. In this paper, we firstly introduce steam injection process briefly. Secondly, a simplified approach of predicting steam pressure in wellbores is presented and a complete expression for steam quality is derived. More importantly, both direct and indirect methods are adopted to determine the wellbore heat efficiency. Then, the mathematical model is solved using an iterative technique. After the model is validated with measured field data, we study the effects of wellhead injection rate and wellhead steam quality on steam injection performance reflected in wellbores. Next, taking cyclic steam stimulation as an example, we analyze steam injection performance reflected in reservoirs with numerical reservoir simulation method. Finally, the significant role of improving wellbore heat efficiency in saving water and fuels is discussed in detail. The results indicate that we can improve the wellbore heat efficiency by enhancing wellhead injection rate or steam quality. However, high wellbore heat efficiency does not necessarily mean satisfactory steam injection performance reflected in reservoirs or good performance of heavy oil recovery. Moreover, the paper shows that using excellent insulation materials is a good way to save water and fuels due to enhancement of wellbore heat efficiency

  2. ESR dating of geyserites from intermittent geyser sites on the Tibetan Plateau

    International Nuclear Information System (INIS)

    Chen, Y.; Feng, J.

    1993-01-01

    Thirteen geyserite samples obtained from two intermittent geyser sites on the Tibetan Plateau were dated by the ESR technique. ESR spectra of geyserite display two sets of signals. One is a set of triplet signals assigned to organic radical X-C-radicalH 2 by Griffiths et al. (1982), another is a mixed signal produced from E'-type defect centres of the silica minerals in geyserite, such as opal, cristobalite, tridymite and quartz. The ages obtained using the mixed E'-type signal are approximately consistent with the stratigraphy and the silica diagenetic sequence. The correlation between the thermal stability of E'-type signal and the mineral association of geyserite was investigated by annealing experiments. (author)

  3. Flora of the Mayacmas Mountains. [Listing of 679 species in the Geysers Geothermal Resource area

    Energy Technology Data Exchange (ETDEWEB)

    Neilson, J.A.

    1981-09-01

    This flora describes the plants that occur within the Mayacmas Mountain Range of northern California. It is the result of ten years of environmental assessment by the author in the Geysers Geothermal Resource area, located in the center of the Mayacmas Range. The flora includes notes on plant communities and ecology of the area, as well as habitat and collection data for most of the 679 species covered. Altogether 74 families, 299 genera and 679 species are included in the flora. The work is divided into eight subdivisions: trees; shrubs; ferns and fern allies; aquatic plants; tules, sedges, and rushes; lilies and related plants; dicot herbs; and grasses. Within each subdivision, family, genera and species are listed alphabetically. Keys are provided at the beginning of each subdivision. A unique combination of physical, environmental and geologic factors have resulted in a rich and diverse flora in the Mayacmas. Maps have been provided indicating known locations for species of rare or limited occurrence.

  4. Hydration of the lower stratosphere by ice crystal geysers over land convective systems

    Directory of Open Access Journals (Sweden)

    S. Khaykin

    2009-03-01

    Full Text Available The possible impact of deep convective overshooting over land has been explored by six simultaneous soundings of water vapour, particles and ozone in the lower stratosphere next to Mesoscale Convective Systems (MCSs during the monsoon season over West Africa in Niamey, Niger in August 2006. The water vapour measurements were carried out using a fast response FLASH-B Lyman-alpha hygrometer. The high vertical resolution observations of the instrument show the presence of accumulation of enhanced water vapour layers between the tropopause at 370 K and the 420 K level. Most of these moist layers are shown connected with overshooting events occurring upwind as identified from satellite IR images over which the air mass probed by the sondes passed during the three previous days. In the case of a local overshoot identified by echo top turrets above the tropopause by the MIT C-band radar also in Niamey, tight coincidence was found between enhanced water vapour, ice crystal and ozone dip layers indicative of fast uplift of tropospheric air across the tropopause. The water vapour mixing ratio in the enriched layers exceeds frequently by 1–3 ppmv the average 6 ppmv saturation ratio at the tropopause and by up to 7 ppmv in the extreme case of local storm in coincidence with the presence of ice crystals. The presence of such layers strongly suggests hydration of the lower stratosphere by geyser-like injection of ice particles over overshooting turrets. The pile-like increase of water vapour up to 19 km seen by the high-resolution hygrometer during the season of maximum temperature of the tropopause, suggests that the above hydration mechanism may contribute to the summer maximum moisture in the lower stratosphere. If this interpretation is correct, hydration by ice geysers across the tropopause might be an important contributor to the stratospheric water vapour budget.

  5. Study with liquid and steam tracers at the Tejamaniles area, Los Azufres, Mich., geothermal field; Estudio con trazadores de liquido y vapor en el area Tejamaniles del campo geotermico de Los Azufres, Mich.

    Energy Technology Data Exchange (ETDEWEB)

    Iglesias, Eduardo R. [Instituto de Investigaciones Electricas, Gerencia de Geotermia, Cuernavaca, Morelos (Mexico)]. E-mail: iglesias@iie.org.mx; Flores Armenta, Magaly [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico); Torres, Rodolfo J. [Instituto de Investigaciones Electricas, Gerencia de Geotermia, Cuernavaca, Morelos (Mexico); Ramirez Montes, Miguel [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico); Reyes Picasso, Neftali [Instituto de Investigaciones Electricas, Gerencia de Geotermia, Cuernavaca, Morelos (Mexico); Reyes Delgado, Lisette [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico)

    2011-01-15

    The Mexican Federal Commission for Electricity injects brines produced by nearby geothermal wells into well Az-08, located in the Tejamaniles area, in the southwestern portion of Los Azufres, Mich., geothermal field. The main goals of this study are to determine whether or not the injected fluid recharges nine producing wells in the area, and if so, to estimate the fraction of the injected fluid recharging each producing well. Five of the selected wells produce mixes of liquid and steam and the rest produce only steam. For this reason, we designed this study with simultaneous injections of liquid- and steam-tracers. The nine selected producing wells detected the steam-tracer, and the five wells producing mixes detected the liquid-phase tracer. The residence curves of both tracers present a series of peaks reflecting the known fractured nature of the reservoir. The results show the feeding areas of the nine selected wells are recharged by the fluid injected into well Az-08. When this paper was written, the arrival of steam-tracers in all wells was completed, but the wells producing mixes of liquid and steam continued to record the arrival of the liquid-tracer. Until 407 days after injecting the tracer, the total percentage recovery of liquid phase tracer in the five wells producing mixes of liquid and steam was 3.5032%. The arrival of the steam tracer ended in all nine wells 205 days after the tracer was injected, with an overall recovery rate of 2.1553 x 10-2%. The recovery rates imply the recharge rates of the monitored wells by the injector Az-08 are modest, but it appears the amounts of the recovered liquid-phase tracer will increase significantly. The modest recovery rates suggest most of the fluid injected into the well Az-08 disperses in the reservoir, contributing to recharge and maintaining the pressure. Results reveal that: (i) the injected fluid is heated at depths from 700 to over 1000 m, where it boils and rises to reach the feeding areas of the

  6. Numerical simulation in steam injection process by a mechanistic approach

    Energy Technology Data Exchange (ETDEWEB)

    De Souza, J.C.Jr.; Campos, W.; Lopes, D.; Moura, L.S.S. [Petrobras, Rio de Janeiro (Brazil)

    2008-10-15

    Steam injection is a common thermal recovery method used in very viscous oil reservoirs. The method involves the injection of heat to reduce viscosity and mobilize oil. A steam generation and injection system consists primarily of a steam source, distribution lines, injection wells and a discarding tank. In order to optimize injection and improve the oil recovery factor, one must determine the parameters of steam flow such as pressure, temperature and steam quality. This study focused on developing a unified mathematical model by means of a mechanistic approach for two-phase steam flow in pipelines and wells. The hydrodynamic and heat transfer mechanistic model was implemented in a computer simulator to model the parameters of steam injection while trying to avoid the use of empirical correlations. A marching algorithm was used to determine the distribution of pressure and temperature along the pipelines and wellbores. The mathematical model for steam flow in injection systems, developed by a mechanistic approach (VapMec) performed well when the simulated values of pressures and temperatures were compared with the values measured during field tests. The newly developed VapMec model was incorporated in the LinVap-3 simulator that constitutes an engineering supporting tool for steam injection wells operated by Petrobras. 23 refs., 7 tabs., 6 figs.

  7. Shiraz solar power plant operation with steam engine

    International Nuclear Information System (INIS)

    Yaghoubi, M.; Azizian, K.

    2004-01-01

    The present industrial developments and daily growing need of energy, as well as economical and environmental problem caused by fossil fuels consumption, resulted certain constraint for the future demand of energy. During the past two decades great attention has been made to use renewable energy for different sectors. In this regard for the first time in Iran, design and construction of a 250 K W Solar power plant in Shiraz, Iran is being carried out and it will go to operation within next year. The important elements of this power plant is an oil cycle and a steam cycle, and several studies have been done about design and operation of this power plant, both for steady state and transient conditions. For the steam cycle, initially a steam turbine was chosen and due to certain limitation it has been replaced by a steam engine. The steam engine is able to produce electricity with hot or saturated vapor at different pressures and temperatures. In this article, the effects of installing a steam engine and changing its vapor inlet pressure and also the effects of sending hot or saturated vapor to generate electricity are studied. Various cycle performance and daily electricity production are determined. The effects of oil cycle temperature on the collector field efficiency, and daily, monthly and annual amount of electricity production is calculated. Results are compared with the steam cycle output when it contains a steam turbine. It is found that with a steam engine it is possible to produce more annual electricity for certain conditions

  8. Steam and electroheating remediation of tight soils

    Energy Technology Data Exchange (ETDEWEB)

    Balshaw-Biddle, K.; Oubre, C.L.; Ward, C.H. [eds.; Dablow, J.F. III; Pearce, J.A.; Johnson, P.C.

    2000-07-01

    In the past few decades the need for soil remediation has become urgent, even more necessary--innovative, cost effective methods. Steam and Electroheating Remediation of Tight Soils presents the results of a field study testing the cleanup of semi-volatile fuels from tight soils using combination of hydraulic fracturing and soil heating technologies.

  9. Steam explosion studies review

    International Nuclear Information System (INIS)

    Hwang, Moon Kyu; Kim, Hee Dong

    1999-03-01

    When a cold liquid is brought into contact with a molten material with a temperature significantly higher than the liquid boiling point, an explosive interaction due to sudden fragmentation of the melt and rapid evaporation of the liquid may take place. This phenomenon is referred to as a steam explosion or vapor explosion. Depending upon the amount of the melt and the liquid involved, the mechanical energy released during a vapor explosion can be large enough to cause serious destruction. In hypothetical severe accidents which involve fuel melt down, subsequent interactions between the molten fuel and coolant may cause steam explosion. This process has been studied by many investigators in an effort to assess the likelihood of containment failure which leads to large scale release of radioactive materials to the environment. In an effort to understand the phenomenology of steam explosion, extensive studies has been performed so far. The report presents both experimental and analytical studies on steam explosion. As for the experimental studies, both small scale tests which involve usually less than 20 g of high temperature melt and medium/large scale tests which more than 1 kg of melt is used are reviewed. For the modelling part of steam explosions, mechanistic modelling as well as thermodynamic modelling is reviewed. (author)

  10. Steam explosion triggering and efficiency studies

    International Nuclear Information System (INIS)

    Buxton, L.D.; Nelson, L.S.; Benedick, W.B.

    1979-01-01

    A program at Sandia Laboratories to provide relevant data on the interaction of molten LWR core materials with water is described. Two different subtasks were established. The first was the performance of laboratory-scale experiments to investigate the ability to trigger steam explosions for realistic LWR core melt simulants under a wide range of initial conditions. The second was the performance of field-scale experiments to investigate the efficiency of converting the thermal energy of the melt into mechanical work in much larger steam explosions

  11. Steam generator tubing NDE performance

    International Nuclear Information System (INIS)

    Henry, G.; Welty, C.S. Jr.

    1997-01-01

    Steam generator (SG) non-destructive examination (NDE) is a fundamental element in the broader SG in-service inspection (ISI) process, a cornerstone in the management of PWR steam generators. Based on objective performance measures (tube leak forced outages and SG-related capacity factor loss), ISI performance has shown a continually improving trend over the years. Performance of the NDE element is a function of the fundamental capability of the technique, and the ability of the analysis portion of the process in field implementation of the technique. The technology continues to improve in several areas, e.g. system sensitivity, data collection rates, probe/coil design, and data analysis software. With these improvements comes the attendant requirement for qualification of the technique on the damage form(s) to which it will be applied, and for training and qualification of the data analysis element of the ISI process on the field implementation of the technique. The introduction of data transfer via fiber optic line allows for remote data acquisition and analysis, thus improving the efficiency of analysis for a limited pool of data analysts. This paper provides an overview of the current status of SG NDE, and identifies several important issues to be addressed

  12. Improvement in using steam for electric generation at the Los Azufres, Mich., geothermal field; Mejora en el aprovechamiento del vapor para generar energia electrica en el campo geotermico de Los Azufres, Mich.

    Energy Technology Data Exchange (ETDEWEB)

    Torres Rodriguez, Marco A.; Flores Armenta, Magaly; Mendoza Covarrubias, Alfredo [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico)]. E-mail: magaly.flores@cfe.gob.mx

    2010-01-15

    Commercial exploitation in the Los Azufres geothermal field, Michoacan, Mexico, started in 1982 when the first five backpressure-power units of 5-MW each were commissioned. Nowadays the installed capacity is 188 MW from 14 units: five in the South Zone fed by steam produced from 18 production wells plus two binary-cycle power units fed by residual brines; and seven in the North Zone with steam supplied by 22 production wells. There are seven backpressure-power units with high specific consumption [between 14.5 and 13.6 tons per hour of steam (t/h) per MW]. Three operate in the South Zone and four in the North Zone. This paper shows a way to achieve more efficient use of the geothermal resource by replacing the seven backpressure units, which have completed their useful lifetime-or are close to do it-with two, new condensing power units with lower specific consumption: one unit of 50 MW to be located in the North Zone and the other of 25 MW to be placed in the South Zone. No new wells need be drilled. In this way, the average specific consumption would be reduced to 8.8-7.2 t/h per MW (saving 47% of the steam), the income for electric generation would be increased and the steam-extraction rate would remain the same. [Spanish] En 1982 empezo la explotacion comercial del campo geotermico de Los Azufres, Mich., Mexico, con la instalacion y puesta en servicio de las primeras cinco unidades turbogeneradoras a contrapresion de 5 MW cada una. Actualmente la capacidad instalada es de 188 MW, con catorce unidades: cinco en la zona sur, alimentadas por el vapor de 18 pozos productores, mas dos unidades de ciclo binario que utilizan salmuera residual, y siete unidades en la zona norte, alimentadas por 22 pozos. Hay siete unidades a contrapresion con un consumo especifico elevado [entre 14.5 y 13.6 toneladas por hora (t/h) de vapor por MW], tres de las cuales se localizan en la zona sur y cuatro en la zona norte. En este documento se presenta un proyecto para hacer mas

  13. Ground penetrating radar documents short-term near-surface hydrological changes around Old Faithful Geyser, Yellowstone National Park, USA

    Science.gov (United States)

    Lynne, Bridget Y.; Heasler, Henry; Jaworowski, Cheryl; Smith, Gary J.; Smith, Isaac J.; Foley, Duncan

    2018-04-01

    In April 2015, Ground Penetrating Radar (GPR) was used to characterize the shallow subsurface (images were collected between two eruptions of Old Faithful Geyser. Each set of time-sequence GPR recordings consisted of four transects aligned to provide coverage near the potential location of the inferred 15 m deep geyser chamber. However, the deepest penetration we could achieve with a 200 MHz GPR antennae was 5 m. Seven time-sequence events were collected over a 48-minute interval to image changes in the near-surface, during pre- and post-eruptive cycles. Time-sequence GPR images revealed a series of possible micro-fractures in a highly porous siliceous sinter in the near-surface that fill and drain repetitively, immediately after an eruption and during the recharge period prior to the next main eruptive event.

  14. Steam generator replacement at Surry Power Station

    International Nuclear Information System (INIS)

    McKay, H.S.

    1982-01-01

    The purposes of the steam generator repair program at Surry Power Station were to repair the tube degradation caused by corrosion-related phenomena and to restore the integrity of the steam generators to a level equivalent to new equipment. The repair program consisted of (1) replacing the existing lower-shell assemblies with new ones and (2) adding new moisture separation equipment to the upper-shell assemblies. These tasks required that several pieces of reactor coolant piping, feedwater piping, main steam piping, and the steam generator be cut and refurbished for reinstallation after the new lower shell was in place. The safety implications and other potential effects of the repair program both during the repair work and after the unit was returned to power were part of the design basis of the repair program. The repair program has been completed on Unit 2 without any adverse effects on the health and safety of the general public or to the personnel engaged in the repair work. Before the Unit 1 repair program began, a review of work procedures and field changes for the Unit 2 repair was conducted. Several major changes were made to avoid recurrence of problems and to streamline procedures. Steam generator replacements was completed on June 1, 1981, and the unit is presently in the startup phase of the outrage

  15. Development of ATSR (Auto Thermal Steam Reformer)

    International Nuclear Information System (INIS)

    Ono, J.; Yoshino, Y.; Kuwabara, T.; Fujisima, S.; Kobayashi, S.; Maruko, S.

    2004-01-01

    'Full text:' Auto-thermal reformers are used popularly for fuel cell vehicle because they are compact and can start up quickly. On the other hand, steam reformers are used for stationary fuel cell power plant because they are good thermal efficiency. While, there are many cases using the auto- thermal reformer for stationary use with expectation of cost reduction in USA, as well. However, they are still insufficient for its durability, compactness and cost. We have been developing the new type of fuel processing system that is auto-thermal steam reformer (ATSR), which is hybrid of a conventional steam reformer (STR) and a conventional auto-thermal reformer (ATR). In this study, some proto-type of ATSR for field test were designed, tried manufacturing and tested performance and durability. And we have tried to operate with fuel cell stack to evaluate the system interface performance, that is, operability and controllability. (author)

  16. Steam generator arrangement

    International Nuclear Information System (INIS)

    Ssinegurski, E.

    1981-01-01

    A steam flow path arrangement for covering the walls of the rear gas pass of a steam generator is disclosed. The entire flow passes down the sidewalls with a minor portion then passing up through the rear wall to a superheater inlet header at an intermediate elevation. The major portion of the flow passes up the front wall and through hanger tubes to a roof header. From there the major portion passes across the roof and down the rear wall to the superheater inlet header at the intermediate elevation

  17. Steam generator sludge removal apparatus

    International Nuclear Information System (INIS)

    Schafer, B.W.; Werner, C.E.; Klahn, F.C.

    1992-01-01

    The present invention relates to equipment for cleaning steam generators and in particular to a high pressure fluid lance for cleaning sludge off the steam generator tubes away from an open tube lane. 6 figs

  18. Steam generators - problems and prognosis

    International Nuclear Information System (INIS)

    Tapping, R.L.

    1997-05-01

    Steam-generator problems, largely a consequence of corrosion and fouling, have resulted in increased inspection requirements and more regulatory attention to steam-generator integrity. In addition, utilities have had to develop steam-generator life-management strategies, including cleaning and replacement, to achieve design life. This paper summarizes the pertinent data to 1993/1994, and presents an overview of current steam-generator management practices. (author)

  19. IAEA activities on steam generator life management

    International Nuclear Information System (INIS)

    Gueorguiev, B.; Lyssakov, V.; Trampus, P.

    2002-01-01

    The International Atomic Energy Agency (IAEA) carries out a set of activities in the field of Nuclear Power Plant (NPP) life management. Main activities within this area are implemented through the Technical Working Group on Life Management of NPPs, and mostly concentrated on studies of understanding mechanisms of degradation and their monitoring, optimisation of maintenance management, economic aspects, proven practices of and approaches to plant life management including decommissioning. The paper covers two ongoing activities related to steam generator life management: the International Database on NPP Steam Generators and the Co-ordinated Research Project on Verification of WWER Steam Generator Tube Integrity (WWER is the Russian designed PWR). The lifetime assessment of main components relies on an ability to assess their condition and predict future degradation trends, which to a large extent is dependent on the availability of relevant data. Effective management of ageing and degradation processes requires a large amount of data. Several years ago the IAEA started to work on the International Database on NPP Life Management. This is a multi-module database consisting of modules such as reactor pressure vessels materials, piping, steam generators, and concrete structures. At present the work on pressure vessel materials, on piping as well as on steam generator is completed. The paper will present the concept and structure of the steam generator module of the database. In countries operating WWER NPPs, there are big differences in the eddy current inspection strategy and practice as well as in the approach to steam generator heat exchanger tube structural integrity assessment. Responding to the need for a co-ordinated research to compare eddy current testing results with destructive testing using pulled out tubes from WWER steam generators, the IAEA launched this project. The main objectives of the project are to summarise the operating experiences of WWER

  20. Steam generator thermal sleeve reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Caton, E.; Askari, A.; Volder, P. [Babcock and Wilcox Canada Ltd., Cambridge, Ontario (Canada)]. E-mail: eecaton@babcock.com

    2003-07-01

    'Full text:' Successful implementation of a physically difficult repair program requires collaboration of the design and construction functions of an organization to ensure that goals are shared and rework or on-the-fly design changes are not required. Furthermore, in a nuclear facility this collaboration results in the optimal safety condition as dose uptake is minimized with a well planned job. The replacement of the degraded thermal sleeves in the Pickering A Steam Generator feedwater nozzles posed this type of problem. The project may be summarized as follows: i) problem analysis, ii) identification of design parameters and limitations, iii) integration of field engineering and design engineering solutions, iv) installation. Integration of the design engineering and field engineering design parameters ensured that the most effective solution was implemented. (author)

  1. Steam reforming of ethanol

    DEFF Research Database (Denmark)

    Trane-Restrup, Rasmus; Dahl, Søren; Jensen, Anker Degn

    2013-01-01

    Steam reforming (SR) of oxygenated species like bio-oil or ethanol can be used to produce hydrogen or synthesis gas from renewable resources. However, deactivation due to carbon deposition is a major challenge for these processes. In this study, different strategies to minimize carbon deposition...

  2. Consolidated nuclear steam generator

    International Nuclear Information System (INIS)

    Jabsen, F.S.; Schluderberg, D.C.; Paulson, A.E.

    1978-01-01

    An improved system of providing power has a unique generating means for nuclear reactors with a number of steam generators in the form of replaceable modular units of the expendable type to attain the optimum in effective and efficient vaporization of fluid during the generating power. The system is most adaptable to undrground power plants and marine usage

  3. Watt steam governor stability

    Science.gov (United States)

    Denny, Mark

    2002-05-01

    The physics of the fly-ball governor, introduced to regulate the speed of steam engines, is here analysed anew. The original analysis is generalized to arbitrary governor geometry. The well-known stability criterion for the linearized system breaks down for large excursions from equilibrium; we show approximately how this criterion changes.

  4. Steam purity in PWRs

    International Nuclear Information System (INIS)

    Hopkinson, J.; Passell, T.

    1982-01-01

    Reports that 2 EPRI studies of PWRs prove that impure steam triggers decay of turbine metals. Reveals that EPRI is attempting to improve steam monitoring and analysis, which are key steps on the way to deciding the most cost-effective degree of steam purity, and to upgrade demineralizing systems, which can then reliably maintain that degree of purity. Points out that 90% of all cracks in turbine disks have occurred at the dry-to-wet transition zone, dubbed the Wilson line. Explains that because even very clean water contains traces of chemical impurities with concentrations in the parts-per-billion range, Crystal River-3's secondary loop was designed with even more purification capability; a deaerator to remove oxygen and prevent oxidation of system metals, and full-flow resin beds to demineralize 100% of the secondary-loop water from the condenser. Concludes that focusing attention on steam and water chemistry can ward off cracking and sludge problems caused by corrosion

  5. Materials choices for the advanced LWR steam generators

    International Nuclear Information System (INIS)

    Paine, J.P.N.; Shoemaker, C.E.; McIlree, A.R.

    1987-01-01

    Current light water reactor (LWR) steam generators have been affected by a variety of corrosion and mechanical damage degradation mechanisms. Included are wear caused by tube vibration, intergranular corrosion, pitting, and thinning or wastage of the steam generator tubing and accelerated corrosion of carbon steel supports (denting). The Electric Power Research Institute (EPRI) and the Steam Generator Owners Groups (I, II) have sponsored laboratory and field studies to provide ameliorative actions for the majority of the damage forms experienced to date. Some of the current corrosion mechanisms are aggravated or caused by unique materials choices or materials interactions. New materials have been proposed and at least partially qualified for use in replacement model steam generators, including an advanced LWR design. In so far as possible, the materials choices for the advanced LWR steam generator avoid the corrosion pitfalls seemingly inherent in the current designs. The EPRI Steam Generator Project staff has recommended materials and design choices for a new steam generator. Based on these recommendations we believe that the advanced LWR steam generators will be much less affected by corrosion and mechanical damage mechanisms than are now experienced

  6. Condensers for measuring steam quality at the inlet of back-pressure units of the Los Azufres, Mich., geothermal field; Condensadores para medir la calidad del vapor a la entrada de las turbinas a contrapresion del campo geotermico de Los Azufres, Mich.

    Energy Technology Data Exchange (ETDEWEB)

    Sandoval Medina, Fernando; Gonzalez Gonzalez, Rubi; Reyes Delgado, Lisette; Medina Martinez, Moises [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Residencia de Los Azufres (Mexico)]. E-mail: fernando.sandoval@cfe.gob.mx

    2007-01-15

    Electrical conductivity is an indirect measurement of the quality of the steam supplied to power units. In the Los Azufres, Mich., geothermal field, the electrical conductivity once was measured in a discrete and periodic way by condensing steam samples through a water-cooled condenser. In an attempt to continuously measure conductivity, conductivity meters were installed where the units discharged, but the values proved unstable and unrepresentative. Thereafter, taking into account that steam quality should be measured at the steam delivery-reception point, equipment was designed and tested for continuously condensing steam. Finally it was possible to get an air-cooled condenser able to condense 500 milliliters per minute, enough to collect a representative flow of the steam and to measure its electrical conductivity. The equipment was installed in all seven back-pressure units operating in the field and to date has been operating in an optimal manner. [Spanish] La conductividad electrica es una medida indirecta de la calidad del vapor que se suministra a las unidades turbogeneradoras. En el campo geotermico de Los Azufres, Mich., la conductividad electrica se media en forma puntual y periodica, condensando muestras de vapor por medio de un serpentin enfriado con agua. Despues, ante la necesidad de medirla en forma continua, se instalaron conductivimetros en las descargas de las unidades, pero los valores resultaron muy inestables y poco representativos. Considerando, ademas, que la calidad del vapor debe medirse en el punto de entrega-recepcion, se disenaron y probaron equipos para condensar vapor de manera continua, lograndose construir un condensador enfriado por aire que logra condensar un flujo de 500 mililitros por minuto, cantidad suficiente para tener un flujo representativo del vapor que alimenta a las turbinas y medirle su conductividad electrica. Se instalaron estos equipos en las siete unidades turbogeneradoras a contrapresion que funcionan en el campo

  7. Steam regulation for 5 MW back-pressure units when a failure occurs in the Los Humeros, Pue., field, Mexico; Regulacion del vapor en caso de falla a unidades a contrapresion de 5 MW en el campo de Los Humeros, Pue., Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Rosales Lopez, Cesar [Comision Federal de Electricidad, Puebla (Mexico)]. E-mail: cesar.rosales@cfe.gob.mx

    2006-07-15

    Four out of the seven back-pressure power units of 5 MW operating in the Los Humeros geothermal field, State of Puebla, Mexico, are fed by one steam pipe gathering the steam produced by nine wells. When a failure occurred in any of the units and the excedence valve had to be open to deviate the steam, a decrease in the steam flow for the remaining units was noted, along with lower electrical generation. The cause for that is analyzed and explained in this paper by comparing the interconnected steam supply system to an electric circuit. A way to maintain a uniform and continuous supply of steam in the Los Humeros field has been found. It was implemented several months ago and the problem has not reoccurred. [Spanish] Cuatro de las siete unidades de 5 MW a contrapresion que operan en el campo geotermico de Los Humeros, Puebla, son alimentadas por un solo vaporducto que reune el vapor de nueve pozos productores. Cuando ocurria una falla en alguna de estas unidades y se abria por completo la valvula de excedencia para desviar el vapor, se observaba una reduccion en el flujo de vapor que llegaba a las otras tres unidades, lo que a su vez ocasionaba que la generacion de electricidad se redujera notoriamente. En este trabajo se analiza y explica la causa de ello, mediante la comparacion de este sistema interconectado de suministro de vapor con un circuito electrico, y se explica la solucion que se encontro e implemento en el campo de Los Humeros para regular el suministro continuo y uniforme de vapor, con resultados satisfactorios a varios meses de su implementacion en las cuatro unidades interconectadas.

  8. Unexplained neurological events during bathing in young people: Possible association with the use of gas geysers

    Directory of Open Access Journals (Sweden)

    Singh Prabhjeet

    2008-01-01

    Full Text Available Here, we report sudden, unexplained neurological collapse in 14 young people while bathing with hot water associated with the use of liquefied petroleum gas (LPG-based water heaters (gas geysers in ill-ventilated bathrooms. None of the patients reported any circumstantial evidence of seizures or prior epilepsy. One patient developed cortical blindness and demonstrated posterior leucoencephalopathy on imaging studies. The remaining patients made rapid and excellent recovery without any residual neurological sequelae. In these cases, the results of all routine investigations, i.e., serum chemistry, brain imaging (computed tomography in 2 and magnetic resonance imaging in 10 and electroencephalography were normal. The clinical clustering of these cases in winter months with similar presentations of reversible encephalopathy probably indicates an inhalational toxin exposure. Therefore, we postulate a hypothesis that harmful emissions consisting of carbon monoxide (CO, hydrocarbon gases (HC and nitrogen oxides (NOx, produced by incomplete combustion of LPG might be responsible for the cellular injury and subsequent transient neurological deficits. Physicians should be aware of this entity in order to avoid misdiagnosis of this condition as seizures, and a public awareness should also be created regarding the proper use of these devices.

  9. Local population impacts of geothermal energy development in the Geysers: Calistoga region

    Energy Technology Data Exchange (ETDEWEB)

    Haven, K.F.; Berg, V.; Ladson, Y.W.

    1980-09-01

    The country-level population increase implications of two long-term geothermal development scenarios for the Geysers region in California are addressed. This region is defined to include the counties of Lake, Sonoma, Mendocino and Napa, all four in northern California. The development scenarios include two components: development for electrical energy production and direct use applications. Electrical production scenarios are derived by incorporating current development patterns into previous development scenarios by both industry and research organizations. The scenarios are made county-specific, specific to the type of geothermal system constructed, and are projected through the year 2000. Separate high growth rate and low growth rate scenarios are developed, based on a set of specified assumptions. Direct use scenarios are estimated from the nature of the available resource, existing local economic and demographic patterns, and available experience with various separate direct use options. From the composite development scenarios, required numbers of direct and indirect employees and the resultant in-migration patterns are estimated. In-migration patterns are compared to current county level population and ongoing trends in the county population change for each of the four counties. From this comparison, conclusions are drawn concerning the contributions of geothermal resource development to future population levels and the significance of geothermally induced population increase from a county planning perspective.

  10. Status of the S.E. Geysers effluent pipeline & injection project

    Energy Technology Data Exchange (ETDEWEB)

    Dellinger, M. [Lake County Sanitation District, Lakeport, CA (United States)

    1997-12-31

    A unique public/private partnership of local, state, federal, and corporate stakeholders is constructing the world`s first wastewater-to-electricity system in Lake County, California. A rare example of a genuinely {open_quotes}sustainable{close_quotes} system, three Lake County communities will recycle their treated wastewater effluent through the Geysers geothermal steamfield to produce an estimated 625,000 MWh of electricity annually from six existing geothermal power plants. The concept is shown schematically. Construction was initiated in October 1995, and as of this writing, the system is approximately 85% complete. Operational start-up is expected in October 1997. The key to the project`s success thus far has been its emphasis on cooperative action among affected stakeholders; and a broad, community-based view of solving problems rather than the traditional, narrower view of engineering-driven technical solutions. Special attention has been given to environmentally-responsive engineering design to avoid or minimize adverse environmental impacts.

  11. Steam generators in PWR's

    International Nuclear Information System (INIS)

    Michel, R.

    1974-01-01

    The steam generator of the PWR operates according to the principle of natural circulation. It consists of a U-shaped tube bundle whose free ends are welded to a bottom plate. The tube bundle is surrounded by a cylinder jacket which has slots closely above the bottom or tube plate. The feed water mixed with boiling water enters the tube bundle through these slots. Because of its buoyancy, the steam-water mixture flows upwards. Below the tube plate there are chambers for distributing and collecting pressurized water separated by means of a partition wall. By omitting some tubes, a free alloy is created so that the tubes in the center get sufficient water, too. By asymmetrical arrangement of the partition wall it is further possible to limit the tube alloy only to the inlet side for pressurized water. The flow over the tube plate is thus improved on the inlet side. (DG) [de

  12. Vertical steam generator

    International Nuclear Information System (INIS)

    Cuda, F.; Kondr, M.; Kresta, M.; Kusak, V.; Manek, O.; Turon, S.

    1982-01-01

    A vertical steam generator for nuclear power plants and dual purpose power plants consists of a cylindrical vessel in which are placed heating tubes in the form upside-down U. The heating tubes lead to the jacket of the cylindrical collector placed in the lower part of the steam generator perpendicularly to its vertical axis. The cylindrical collector is divided by a longitudinal partition into the inlet and outlet primary water sections of the heating tubes. One ends of the heating tube leads to the jacket of the collector for primary water feeding and the second ends of the heating tubes into the jacket of the collector which feeds and offtakes primary water from the heating tubes. (B.S.)

  13. Practical aspects of steam injection processes: A handbook for independent operators

    Energy Technology Data Exchange (ETDEWEB)

    Sarathi, P.S.; Olsen, D.K.

    1992-10-01

    More than 80% of the total steam injection process operating costs are for the production of steam and the operation of surface and subsurface equipment. The proper design and operation of the surface equipment is of critical importance to the success of any steam injection operation. However, the published monographs on thermal recovery have attached very little importance to this aspect of thermal oil recovery; hence, a definite need exists for a comprehensive manual that places emphasis on steam injection field practices and problems. This handbook is an attempt to fulfill this need. This handbook explores the concept behind steam injection processes and discusses the information required to evaluate, design, and implement these processes in the field. The emphasis is on operational aspects and those factors that affect the technology and economics of oil recovery by steam. The first four chapters describe the screening criteria, engineering, and economics of steam injection operation as well as discussion of the steam injection fundamentals. The next four chapters begin by considering the treatment of the water used to generate steam and discuss in considerable detail the design, operation and problems of steam generations, distribution and steam quality determination. The subsurface aspects of steamflood operations are addressed in chapters 9 through 12. These include thermal well completion and cementing practices, insulated tubulars, and lifting equipment. The next two chapters are devoted to subsurface operational problems encountered with the use of steam. Briefly described in chapters 15 and 16 are the steam injection process surface production facilities, problems and practices. Chapter 17 discusses the importance of monitoring in a steam injection project. The environmental laws and issues of importance to steam injection operation are outlined in chapter 18.

  14. Steam generator life management

    International Nuclear Information System (INIS)

    King, P.; McGillivray, R.; Reinhardt, W.; Millman, J.; King, B.; Schneider, W.

    2003-01-01

    'Full-Text:' Steam Generator Life Management responsibility embodies doing whatever is necessary to maintain the steam generation equipment of a nuclear plant in effective, reliable service. All comes together in that most critical deliverable, namely the submission of the documentation which wins approval for return to service after an outage program. Life management must address all aspects of SG reliability over the life of the plant. Nevertheless, the life management activities leading up to return to service approval is where all of it converges. Steam Generator Life Management activities entail four types of work, all equally important in supporting the objective of successful operation. These activities are i) engineering functions; including identification of inspection and maintenance requirements, outage planning and scope definition plus engineering assessment, design and analysis as necessary to support equipment operation, ii) fitness of service work; including the expert evaluation of degradation mechanisms, disposition of defects for return to service or not, and the fitness for service analysis as required to justify ongoing operation with acceptable defects, iii) inspection work; including large scale eddy current inspection of tubing, the definition of defect size and character, code inspections of pressure vessel integrity and visual inspections for integrity and iv) maintenance work; including repairs, retrofits, cleaning and modifications, all as necessary to implement the measures defined during activities i) through iii). The paper discusses the approach and execution of the program for the achievement of the above objectives and particularly of items i) and ii). (author)

  15. What is geothermal steam worth?

    International Nuclear Information System (INIS)

    Thorhallsson, S.; Ragnarsson, A.

    1992-01-01

    Geothermal steam is obtained from high-temperature boreholes, either directly from the reservoir or by flashing. The value of geothermal steam is similar to that of steam produced in boilers and lies in its ability to do work in heat engines such as turbines and to supply heat for a wide range of uses. In isolated cases the steam can be used as a source of chemicals, for example the production of carbon dioxide. Once the saturated steam has been separated from the water, it can be transported without further treatment to the end user. There are several constraints on its use set by the temperature of the reservoir and the chemical composition of the reservoir fluid. These constraints are described (temperature of steam, scaling in water phase, gas content of steam, well output) as are the methods that have been adopted to utilize this source of energy successfully. Steam can only be transported over relatively short distances (a few km) and thus has to be used close to the source. Examples are given of the pressure drop and sizing of steam mains for pipelines. The path of the steam from the reservoir to the end user is traced and typical cost figures given for each part of the system. The production cost of geothermal steam is estimated and its sensitivity to site-specific conditions discussed. Optimum energy recovery and efficiency is important as is optimizing costs. The paper will treat the steam supply system as a whole, from the reservoir to the end user, and give examples of how the site-specific conditions and system design have an influence on what geothermal steam is worth from the technical and economic points of view

  16. Wet steam wetness measurement in a 10 MW steam turbine

    Directory of Open Access Journals (Sweden)

    Kolovratník Michal

    2014-03-01

    Full Text Available The aim of this paper is to introduce a new design of the extinction probes developed for wet steam wetness measurement in steam turbines. This new generation of small sized extinction probes was developed at CTU in Prague. A data processing technique is presented together with yielded examples of the wetness distribution along the last blade of a 10MW steam turbine. The experimental measurement was done in cooperation with Doosan Škoda Power s.r.o.

  17. Super titanium blades for advanced steam turbines

    International Nuclear Information System (INIS)

    Coulon, P.A.

    1990-01-01

    In 1986, the Alsthom Steam Turbines Department launched the manufacture of large titanium alloy blades: airfoil length of 1360 mm and overall length of 1520 mm. These blades are designed for the last-stage low pressure blading of advanced steam turbines operating at full speed (3000 rpm) and rating between 300 and 800 MW. Using titanium alloys for steam turbine exhaust stages as substitutes for chrome steels, due to their high strength/density ratio and their almost complete resistance to corrosion, makes it possible to increase the length of blades significantly and correspondingly that steam passage section (by up to 50%) with a still conservative stresses level in the rotor. Alsthom relies on 8 years of experience in the field of titanium, since as early as 1979 large titanium blades (airfoil length of 1240 mm, overall length of 1430 mm) were erected for experimental purposes on the last stage of a 900 MW unit of the Dampierre-sur-Loire power plant and now totals 45,000 operating hours without problems. The paper summarizes the main properties (chemical, mechanical and structural) recorded on very large blades and is based in particular on numerous fatigue corrosion test results to justify the use of the Ti 6 Al 4 V alloy in a specific context of micrographic structure

  18. Analysis of fast reactor steam generator performance

    International Nuclear Information System (INIS)

    Hulme, G.; Curzon, A.F.

    1992-01-01

    A computer model for the prediction of flow and temperature fields within a fast reactor steam generator unit is described. The model combines a commercially available computational fluid dynamics (CFD) solver (PHOENICS) with a steam-tube calculation and provides solutions for the fully coupled flow and temperature fields on both the shell side and the tube side. The model includes the inlet and outlet headers and the bottom end stagnant zone. It also accounts for the effects of support grids and edge-gaps. Two and three dimensional and transient calculations have been performed for both straight tube and J-tube units. Examples of the application of the model are presented. (7 figures) (Author)

  19. Steam generators, turbines, and condensers. Volume six

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    Volume six covers steam generators (How steam is generated, steam generation in a PWR, vertical U-tube steam generators, once-through steam generators, how much steam do steam generators make?), turbines (basic turbine principles, impulse turbines, reaction turbines, turbine stages, turbine arrangements, turbine steam flow, steam admission to turbines, turbine seals and supports, turbine oil system, generators), and condensers (need for condensers, basic condenser principles, condenser arrangements, heat transfer in condensers, air removal from condensers, circulating water system, heat loss to the circulating water system, factors affecting condenser performance, condenser auxiliaries)

  20. Five-component propagation model for steam explosion analysis

    International Nuclear Information System (INIS)

    Yang, Y.; Moriyama, Kiyofumi; Park, H.S.; Maruyama, Yu; Sugimoto, Jun

    1999-01-01

    A five-field simulation code JASMINE-pro has been developed at JAERI for the calculation of the propagation and explosion phase of steam explosions. The basic equations and the constitutive relationships specifically utilized in the propagation models in the code are introduced in this paper. Some calculations simulating the KROTOS 1D and 2D steam explosion experiments are also stated in the paper to show the present capability of the code. (author)

  1. Structure of steam water mixture spray

    International Nuclear Information System (INIS)

    Mitsuhashi, Yuki; Mizutani, Hiroya; Sanada, Toshiyuki; Saito, Takayuki

    2008-01-01

    The flow structure of steam and water mixture spray is studied both numerically and experimentally. The velocity and pressure profiles of the single phase flow are calculated using numerical methods. Using calculated flow fields, the droplet behavior is predicted by the one-way interaction model. This numerical analysis clarifies that the droplets are still accelerated after they are sprayed from the nozzle. In the experiments, the spray of the mixture is observed by using ultra high-speed video camera, and the velocity field is measured by using PIV technique. Along with this PIV velocity field measurement, the velocities and diameters of droplets are measured by phase Doppler anemometry. Furthermore, mixing process of steam and water, and atomization process of liquid film are observed through the transparent nozzle. The high-speed photography observation reveals that the flow inside the nozzle forms the annular flow and the most of the liquid film is atomized at the nozzle outlet. Finally, the optimum method of processing mixture of steam and water is proposed. (author)

  2. Estimation of steam-chamber extent using 4D seismic

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, M. [Waseda Univ., Waseda (Japan); Endo, K. [Japan Canada Oil Sands Ltd., Calgary, AB (Canada); Onozuka, S. [Japan Oil, Gas and Metals National Corp., Tokyo (Japan)

    2009-07-01

    The steam-assisted gravity drainage (SAGD) technique is among the most effective steam injection methods and is widely applied in Canadian oil-sand reservoirs. The SAGD technology uses hot steam to decrease bitumen viscosity and allow it to flow. Japan Canada Oil Sands Limited (JACOS) has been developing an oil-sand reservoir in the Alberta's Hangingstone area since 1997. This paper focused on the western area of the reservoir and reported on a study that estimated the steam-chamber extent generated by horizontal well pairs. It listed steam injection start time for each well of the western area. Steam-chamber distribution was determined by distinguishing high temperature and high pore-pressure zones from low temperature and high pore-pressure zones. The bitumen recovery volume in the steam-chamber zone was estimated and compared with the actual cumulative production. This paper provided details of the methodology and interpretation procedures for the quantitative method to interpret 4D-seismic data for a SAGD process. A procedure to apply a petrophysical model was demonstrated first by scaling laboratory measurements to field-scale applications, and then by decoupling pressure and temperature effects. The first 3D seismic data in this study were already affected by higher pressures and temperatures. 11 refs., 3 tabs., 12 figs.

  3. The Wheel Model of STEAM Education Based on Traditional Korean Scientific Contents

    Science.gov (United States)

    Kim, Pyoung Won

    2016-01-01

    The Korean STEAM education pursues a convergent human resources education, but there are shortcomings associated with it due to the fact that it excludes the Humanities in its curriculum. This study embodies the accomplishments from the design and field application of the STEAM education model that has added Humanities fields (history, geography,…

  4. Steam generator tube performance

    International Nuclear Information System (INIS)

    Tatone, O.S.; Pathania, R.S.

    1984-10-01

    A review of the performance of steam generator tubes in 116 water-cooled nuclear power reactors showed that tubes were plugged at 54 (46 percent) of the reactors. The number of tubes removed from service decreased from 4 692 (0.30 percent) in 1981 to 3 222 (0.20 percent) in 1982. The leading causes of tube failures were stress corrosion cracking from the primary side, stress corrosion cracking (or intergranular attack) from the secondary side and pitting corrosion. The lowest incidence of corrosion-induced defects from the secondary side occurred in reactors that have used only volatile treatment, with or without condensate demineralization

  5. Steam generator tube performance

    International Nuclear Information System (INIS)

    Tatone, O.S.; Tapping, R.L.; Stipan, L.

    1992-03-01

    A survey of steam generator operating experience for 1986 has been carried out for 184 pressurized water and pressurized heavy-water reactors, and 1 water-cooled, graphite-moderated reactor. Tubes were plugged at 75 of the reactors (40.5%). In 1986, 3737 tubes were plugged (0.14% of those in service) and 3148 tubes were repaired by sleeving. A small number of reactors accounted for the bulk of the plugged tubes, a phenomenon consistent with previous years. For 1986, the available tubesheet sludge data for 38 reactors has been compiled into tabular form, and sludge/deposit data will be incorporated into all future surveys

  6. Steam generator auxiliary systems

    International Nuclear Information System (INIS)

    Heinz, A.

    1982-01-01

    The author deals with damage and defect types obtaining in auxiliary systems of power plants. These concern water/steam auxiliary systems (feed-water tank, injection-control valves, slide valves) and air/fluegas auxiliary systems (blowers, air preheaters, etc.). Operating errors and associated damage are not dealt with; by contrast, weak spots are pointed out which result from planning and design. Damage types and events are collected in statistics in order to facilitate damage evaluation for arriving at improved design solutions. (HAG) [de

  7. DEMONSTRATION BULLETIN STEAM ENHANCED REMEDIATION STEAM TECH ENVIRONMENTAL SERVICES, INC.

    Science.gov (United States)

    Steam Enhanced Remediation is a process in which steam is injected into the subsurface to recover volatile and semivolatile organic contaminants. It has been applied successfully to recover contaminants from soil and aquifers and at a fractured granite site. This SITE demonstra...

  8. Steam generators: critical components in nuclear steam supply systems

    Energy Technology Data Exchange (ETDEWEB)

    Stevens-Guille, P D

    1974-02-28

    Steam generators are critical components in power reactors. Even small internal leaks result in costly shutdowns for repair. Surveys show that leaks have affected one half of all water-cooled reactors in the world with steam generators. CANDU reactors have demonstrated the highest reliability. However, AECL is actively evolving new technology in design, manufacture, inspection and operation to maintain reliability. (auth)

  9. Optimization of the recovery factor by implementing a continuous steam injection pilot in the Huyapari Field located in the Orinoco oil belt. Venezuela

    Energy Technology Data Exchange (ETDEWEB)

    Li, L.; Munckton, T.; Armas, F.; Johan, J.; Barrios, A. [PDVSA PetroPiar (Venezuela)

    2011-07-01

    Located in Venezuela, the Orinoco heavy oil belt (Faja) is one of the world's biggest accumulations of extra heavy crude oil. Recovery rates in the Faja are relatively low and so one of the key objectives is to increase it. The thermal recovery process could be a way to increase production as it has been proven in other heavy oil fields and PDVSA has started a pilot project to test the process on the Faja reservoirs. This paper aimed at providing an overview of the project. The different steps of the Huyapari thermal pilot project are discussed: the objectives and challenges of the project, project design, uncertainty management, site selection, modeling of the site subsurface and optimization planning in terms of well configuration and constraints. This project is under development and further steps will be required before there are results but when there are, it is expected that they will provide valuable information on the technical and economic feasibility of thermal recovery projects in the Faja area.

  10. Flow characteristics in nuclear steam turbine blade passage

    International Nuclear Information System (INIS)

    Ahn, H.J.; Yoon, W.H.; Kwon, S.B.

    1995-01-01

    The rapid expansion of condensable gas such as moist air or steam gives rise to nonequilibrium condensation. As a result of irreversibility of condensation process in the nuclear steam turbine blade passage, the entropy of the flow increases, and the efficiency of the turbine decreases. In the present study, in order to investigate the flow characteristics of moist air in two-dimensional turbine blade passage which is made from the configuration of the last stage tip section of the actual nuclear steam turbine moving blade, the static pressures along both pressure and suction sides of blade are measured by static pressure taps and the distribution of Mach number on both sides of the blade are obtained by using the measured static pressure. Also, the flow field is visualized by a Schlieren system. From the experimental results, the effects of the stagnation temperature and specific humidity on the flow properties in the two dimensional steam turbine blade passage are clearly identified

  11. Steam hydrocarbon cracking and reforming

    NARCIS (Netherlands)

    Golombok, M.

    2004-01-01

    Many industrial chemical processes are taught as distinct contrasting reactions when in fact the unifying comparisons are greater than the contrasts. We examine steam hydrocarbon reforming and steam hydrocarbon cracking as an example of two processes that operate under different chemical reactivity

  12. Steam Generator Group Project. Annual report, 1982

    International Nuclear Information System (INIS)

    Clark, R.A.; Lewis, M.

    1984-02-01

    The Steam Generator Group Project (SGGP) is an NRC program joined by additional sponsors. The SGGP utilizes a steam generator removed from service at a nuclear plant (Surry 2) as a vehicle for research on a variety of safety and reliability issues. This report is an annual summary of progress of the program for 1982. Information is presented on the Steam Generator Examination Facility (SGEF), especially designed and constructed for this research. Loading of the generator into the SGEF is then discussed. The report then presents radiological field mapping results and personnel exposure monitoring. This is followed by information on field reduction achieved by channel head decontaminations. The report then presents results of a secondary side examination through shell penetrations placed prior to transport, confirming no change in generator condition due to transport. Decontamination of the channel head is discussed followed by plans for eddy current testing and removal of the plugs placed during service. Results of a preliminary profilometry examination are then provided

  13. Three Steam Generator Replacement Projects in 1995

    International Nuclear Information System (INIS)

    Holz, R.; Clavier, G.

    1996-01-01

    Since the companies Siemens AG and Framatome S. A. joined their experience and efforts in the field of steam generator replacements and formed a consortium in 1991, the following projects were performed in 1995: Ringhals 3, Tihange 3 and Asco 1. Further projects will follow in 1996, i. e., Doel 4 and Asco 2. Currently, this European consortium is bidding for the contract to replace the steam generators at the Krsko NPP and hopes to be awarded in 1996. An overview of the way the Consortium Siemens and Framatome approaches SG replacement projects is given based on the projects performed in 1995. Various aspects of project planning, management, licensing, personnel qualification and techniques used on site will be discussed. (author)

  14. Steam generator reliability improvement project

    International Nuclear Information System (INIS)

    Blomgren, J.C.; Green, S.J.

    1987-01-01

    Upon successful completion of its research and development technology transfer program, the Electric Power Research Institute's Steam Generator Owners Group (SGOG II) will disband in December 1986 and be replaced in January 1987 by a successor project, the Steam Generator Reliability Project (SGRP). The new project, funded in the EPRI base program, will continue the emphasis on reliability and life extension that was carried forward by SGOG II. The objectives of SGOG II have been met. Causes and remedies have been identified for tubing corrosion problems, such as stress corrosion cracking and pitting, and steam generator technology has been improved in areas such as tube wear prediction and nondestructive evaluation (NDE). These actions have led to improved reliability of steam generators. Now the owners want to continue with a centrally managed program that builds on what has been learned. The goal is to continue to improve steam generator reliability and solve small problems before they become large problems

  15. Steam generator reliability improvement project

    International Nuclear Information System (INIS)

    Blomgren, J.C.; Green, S.J.

    1987-01-01

    Upon successful completion of its research and development technology transfer program, the Electric Power Research Institute's (EPRI's) Steam Generator Owners Group (SGOG II) will disband in December 1986, and be replaced in January 1987, by a successor project, the Steam Generator Reliability Project (SGRP). The new project, funded in the EPRI base program, will continue to emphasize reliability and life extension, which were carried forward by SGOG II. The objectives of SGOG II have been met. Causes and remedies have been identified for tubing corrosion problems such as stress corrosion cracking and pitting, and steam generator technology has been improved in areas such as tube wear prediction and nondestructive evaluation. These actions have led to improved reliability of steam generators. Now the owners want to continue with a centrally managed program that builds on what has been learned. The goal is to continue to improve steam generator reliability and to solve small problems before they become large problems

  16. Steam generator tube integrity program

    International Nuclear Information System (INIS)

    Dierks, D.R.; Shack, W.J.; Muscara, J.

    1996-01-01

    A new research program on steam generator tubing degradation is being sponsored by the U.S. Nuclear Regulatory Commission (NRC) at Argonne National Laboratory. This program is intended to support a performance-based steam generator tube integrity rule. Critical areas addressed by the program include evaluation of the processes used for the in-service inspection of steam generator tubes and recommendations for improving the reliability and accuracy of inspections; validation and improvement of correlations for evaluating integrity and leakage of degraded steam generator tubes, and validation and improvement of correlations and models for predicting degradation in steam generator tubes as aging occurs. The studies will focus on mill-annealed Alloy 600 tubing, however, tests will also be performed on replacement materials such as thermally-treated Alloy 600 or 690. An overview of the technical work planned for the program is given

  17. Steam injections wells: topics to consider in casing design of steam injection wells; Revestimento para pocos de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Conceicao, Antonio Carlos Farias [PETROBRAS, Recife, PE (Brazil). Gerencia de Perfuracao do Nordeste. Div. de Operacoes

    1994-07-01

    Steam injection is one of the processes used to increase production from very viscous oil reservoirs. A well is completed at a temperature of about 110 deg F and during steam injection that temperature varies around 600 deg F. Strain or breakdowns may occur to the casing, due to the critical conditions generated by the change of temperature. The usual casing design methods, do not take into account special environmental conditions, such as those which exist for steam injection. From the results of this study we come up to the conclusion that casing grade K-55, heavy weight with premium connections, without pre-stressing and adequately heated, is the best option for steam injection well completion for most of the fields in Brazil. (author)

  18. On calculation of a steam-water flow in a geothermal well

    Science.gov (United States)

    Shulyupin, A. N.; Chermoshentseva, A. A.

    2013-08-01

    Approaches to calculation of a steam-water flow in a geothermal well are considered. For hydraulic applications, a WELL-4 model of a steam-water well is developed. Data obtained using this model are compared with experimental data and also with calculations by similar models including the well-known HOLA model. The capacity of the A-2 well in the Mutnovskoe flash-steam field (Kamchatka half-island, Russia) after planned reconstruction is predicted.

  19. An Improved Steam Injection Model with the Consideration of Steam Override

    OpenAIRE

    He , Congge; Mu , Longxin; Fan , Zifei; Xu , Anzhu; Zeng , Baoquan; Ji , Zhongyuan; Han , Haishui

    2017-01-01

    International audience; The great difference in density between steam and liquid during wet steam injection always results in steam override, that is, steam gathers on the top of the pay zone. In this article, the equation for steam override coefficient was firstly established based on van Lookeren’s steam override theory and then radius of steam zone and hot fluid zone were derived according to a more realistic temperature distribution and an energy balance in the pay zone. On this basis, th...

  20. Steam generator tube performance

    International Nuclear Information System (INIS)

    Tatone, O.S.; Pathania, R.S.

    1982-04-01

    The performance of steam generator tubes in water-cooled nuclear power reactors has been reviewed for 1980. Tube defects occurred at 38% of the 97 reactors surveyed. This is a marginal improvement over 1979 when defects occurred at 41% of the reactors. The number of failed tubes was also lower, 0.14% of the tubes in service in 1980 compared with 0.20% of those in service in 1979. Analysis of the causes of these failures indicates that stress corrosion cracking was the leading failure mechanism. Reactors that used all-volatile treatment of secondary water, with or without full-flow condensate demineralization since start-up showed the lowest incidence of corrosion-related defects

  1. Steam generator tube performance

    International Nuclear Information System (INIS)

    Tatone, O.S.; Pathania, R.S.

    1983-08-01

    A review of the performance of steam generator tubes in 110 water-cooled nuclear power reactors showed that tubes were plugged at 46 (42 percent) of the reactors. The number of tubes removed from service increased from 1900 (0.14 percent) in 1980 to 4692 (0.30 percent) in 1981. The leading causes of tube failures were stress corrosion cracking from the primary side, stress corrosion cracking (or intergranular attack) from the secondary side and pitting corrosion. The lowest incidence of corrosion-induced defects from the secondary side occurred in reactors that used all-volatile treatment since start-up. At one reactor a large number of degraded tubes were repaired by sleeving which is expected to become an important method of tube repair in the future

  2. Erosion corrosion in wet steam

    International Nuclear Information System (INIS)

    Tavast, J.

    1988-03-01

    The effect of different remedies against erosion corrosion in wet steam has been studied in Barsebaeck 1. Accessible steam systems were inspected in 1984, 1985 and 1986. The effect of hydrogen peroxide injection of the transport of corrosion products in the condensate and feed water systems has also been followed through chemical analyses. The most important results of the project are: - Low alloy chromium steels with a chromium content of 1-2% have shown excellent resistance to erosion corrosion in wet steam. - A thermally sprayed coating has shown good resistance to erosion corrosion in wet steam. In a few areas with restricted accessibility minor attacks have been found. A thermally sprayed aluminium oxide coating has given poor results. - Large areas in the moisture separator/reheater and in steam extraction no. 3 have been passivated by injection of 20 ppb hydrogen peroxide to the high pressure steam. In other inspected systems no significant effect was found. Measurements of the wall thickness in steam extraction no. 3 showed a reduced rate of attack. - The injection of 20 ppb hydrogen peroxide has not resulted in any significant reduction of the iron level result is contrary to that of earlier tests. An increase to 40 ppb resulted in a slight decrease of the iron level. - None of the feared disadvantages with hydrogen peroxide injection has been observed. The chromium and cobalt levels did not increase during the injection. Neither did the lifetime of the precoat condensate filters decrease. (author)

  3. CANDU steam generator life management

    International Nuclear Information System (INIS)

    Tapping, R.L.; Nickerson, J.; Spekkens, P.; Maruska, C.

    1998-01-01

    Steam generators are a critical component of a nuclear power reactor, and can contribute significantly to station unavailability, as has been amply demonstrated in Pressurized Water Reactors (PWRs). CANDU steam generators are not immune to steam generator degradation, and the variety of CANDU steam generator designs and tube materials has led to some unexpected challenges. However, aggressive remedial actions, and careful proactive maintenance activities, have led to a decrease in steam generator-related station unavailability of Canadian CANDUs. AECL and the CANDU utilities have defined programs that will enable existing or new steam generators to operate effectively for 40 years. Research and development work covers corrosion and mechanical degradation of tube bundles and internals, chemistry, thermalhydraulics, fouling, inspection and cleaning, as well as provision for specially tool development for specific problem solving. A major driving force is development of CANDU-specific fitness-for-service guidelines, including appropriate inspection and monitoring technology to measure steam generator condition. Longer-range work focuses on development of intelligent on-line monitoring for the feedwater system and steam generator. New designs have reduced risk of corrosion and fouling, are more easily inspected and cleaned, and are less susceptible to mechanical damage. The Canadian CANDU utilities have developed programs for remedial actions to combat degradation of performance (Gentilly-2, Point Lepreau, Bruce A/B, Pickering A/B), and have developed strategic plans to ensure that good future operation is ensured. The research and development program, as well as operating experience, has identified where improvements in operating practices and/or designs can be made in order to ensure steam generator design life at an acceptable capacity factory. (author)

  4. Advanced technologies on steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Sakata, Kaoru; Nakamura, Yuuki [Mitsubishi Heavy Industry Co., Takasago (Japan); Nakamori, Nobuo; Mizutani, Toshiyuki; Uwagawa, Seiichi; Saito, Itaru [Mitsubishi Heavy Industry Co., Kobe (Japan); Matsuoka, Tsuyoshi [Mitsubishi Heavy Industry Co., Yokohama (Japan)

    1997-12-31

    The thermal-hydraulic tests for a horizontal steam generator of a next-generation PWR (New PWR-21) were performed. The purpose of these tests is to understand the thermal-hydraulic behavior in the secondary side of horizontal steam generator during the plant normal operation. A test was carried out with cross section slice model simulated the straight tube region. In this paper, the results of the test is reported, and the effect of the horizontal steam generator internals on the thermalhydraulic behavior of the secondary side and the circulation characteristics of the secondary side are discussed. (orig.). 3 refs.

  5. Steam reformer with catalytic combustor

    Science.gov (United States)

    Voecks, Gerald E. (Inventor)

    1990-01-01

    A steam reformer is disclosed having an annular steam reforming catalyst bed formed by concentric cylinders and having a catalytic combustor located at the center of the innermost cylinder. Fuel is fed into the interior of the catalytic combustor and air is directed at the top of the combustor, creating a catalytic reaction which provides sufficient heat so as to maintain the catalytic reaction in the steam reforming catalyst bed. Alternatively, air is fed into the interior of the catalytic combustor and a fuel mixture is directed at the top. The catalytic combustor provides enhanced radiant and convective heat transfer to the reformer catalyst bed.

  6. Advanced technologies on steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Sakata, Kaoru; Nakamura, Yuuki [Mitsubishi Heavy Industry Co., Takasago (Japan); Nakamori, Nobuo; Mizutani, Toshiyuki; Uwagawa, Seiichi; Saito, Itaru [Mitsubishi Heavy Industry Co., Kobe (Japan); Matsuoka, Tsuyoshi [Mitsubishi Heavy Industry Co., Yokohama (Japan)

    1998-12-31

    The thermal-hydraulic tests for a horizontal steam generator of a next-generation PWR (New PWR-21) were performed. The purpose of these tests is to understand the thermal-hydraulic behavior in the secondary side of horizontal steam generator during the plant normal operation. A test was carried out with cross section slice model simulated the straight tube region. In this paper, the results of the test is reported, and the effect of the horizontal steam generator internals on the thermalhydraulic behavior of the secondary side and the circulation characteristics of the secondary side are discussed. (orig.). 3 refs.

  7. Integrated steam generation process and system for enhanced oil recovery

    Energy Technology Data Exchange (ETDEWEB)

    Betzer-Zilevitch, M. [Ex-Tar Technologies Inc., Calgary, AB (Canada)

    2010-07-01

    A method of producing steam for the extraction of heavy bitumens was presented. The direct contact steam generation (DCSG) method is used for the direct heat transfer between combustion gas and contaminated liquid phase water to generate steam. This paper presented details of experimental and field studies conducted to demonstrate the DCSG. Results of the study demonstrated that pressure and temperature are positively correlated. As pressure increases, the flow rate of the discharged mass decreases and the steam ratio decreases. As pressure increases, the condensate and distillate flow rates increases while water vapor losses in the non-condensable gases decrease. The study indicated that for a 10 bar pressurized system producing 9.6 mt per hour of 10,000 kpa steam and 9.6 mt per hour of distillate BFW, 70 percent of the combustion energy should be recovered to generate 10,000 kpa pressure steam for EOR. Combustion energy requirements were found to decrease when pressure decreases. 11 refs., 5 tabs., 8 figs.

  8. Materials performance in operating PWR steam generators

    International Nuclear Information System (INIS)

    Weeks, J.R.

    1975-01-01

    The Inconel-600 tubing in operating PWR steam generators has developed leaks due to intergranular stress corrosion cracking or a general wastage attack, originating from the secondary side of the tubing. Corrosion has been limited to those areas of the steam generators where limited coolant circulation and high heat flux have caused impurities to concentrate. Wastage or pitting attack has always been associated with local concentration of sodium hydrogen phosphates, whereas stress corrosion has been associated with local concentration of sodium or potassium hydroxides. The only instance of stress corrosion originating from the primary side occurred on cold-worked tubing when hydrogen was not added to getter oxygen, and LiOH was not added to raise the pH of the primary coolant. All PWR manufacturers are now recommending that the phosphate treatment of the secondary coolant be abandoned in favor of an all-volatile treatment. Experience in operating plants has shown, however, that removal of phosphate-rich sludge deposits is difficult, and that further wastage and/or intergranular stress corrosion may develop; the residual sodium phosphates gradually convert by reaction with corrosion product hydroxides to sodium hydroxide, which remains concentrated in the limited flow areas. Improvements in circulation patterns have been achieved by inserting flow baffles in some PWR steam generators. Inservice monitoring by eddy current techniques is useful for detecting corrosion-induced defects in the tubing, but irreproducibility in field examinations can lead to uncertainties interpreting the results. (U.S.)

  9. Fuqing nuclear power of nuclear steam turbine generating unit No.1 at the implementation and feedback

    International Nuclear Information System (INIS)

    Cao Yuhua; Xiao Bo; He Liu; Huang Min

    2014-01-01

    The article introduces the Fuqing nuclear power of nuclear steam turbine generating unit no.l purpose, range of experience, experiment preparation, implementation, feedback and response. Turn of nuclear steam turbo-generator set flush, using the main reactor coolant pump and regulator of the heat generated by the electric heating element and the total heat capacity in secondary circuit of reactor coolant system (steam generator secondary side) of saturated steam turbine rushed to 1500 RPM, Fuqing nuclear power of nuclear steam turbine generating unit no.1 implementation of the performance of the inspection of steam turbine and its auxiliary system, through the test problems found in the clean up in time, the nuclear steam sweep turn smooth realization has accumulated experience. At the same time, Fuqing nuclear power of nuclear steam turbine generating unit no.1 at turn is half speed steam turbine generator non-nuclear turn at the first, with its smooth realization of other nuclear power steam turbine generator set in the field of non-nuclear turn play a reference role. (authors)

  10. Wet-steam erosion of steam turbine disks and shafts

    International Nuclear Information System (INIS)

    Averkina, N. V.; Zheleznyak, I. V.; Kachuriner, Yu. Ya.; Nosovitskii, I. A.; Orlik, V. G.; Shishkin, V. I.

    2011-01-01

    A study of wet-steam erosion of the disks and the rotor bosses or housings of turbines in thermal and nuclear power plants shows that the rate of wear does not depend on the diagrammed degree of moisture, but is determined by moisture condensing on the surfaces of the diaphragms and steam inlet components. Renovating the diaphragm seals as an assembly with condensate removal provides a manifold reduction in the erosion.

  11. Regulation of ageing steam generators

    International Nuclear Information System (INIS)

    Jarman, B.L.; Grant, I.M.; Garg, R.

    1998-01-01

    Recent years have seen leaks and shutdowns of Canadian CANDU plants due to steam generator tube degradation by mechanisms including stress corrosion cracking, fretting and pitting. Failure of a single steam generator tube, or even a few tubes, would not be a serious safety related event in a CANDU reactor. The leakage from a ruptured tube is within the makeup capacity of the primary heat transport system, so that as long as the operator takes the correct actions, the off-site consequences will be negligible. However, assurance that no tubes deteriorate to the point where their integrity could be seriously breached as result of potential accidents, and that any leakage caused by such an accident will be small enough to be inconsequential, can only be obtained through detailed monitoring and management of steam generator condition. This paper presents the AECB's current approach and future regulatory directions regarding ageing steam generators. (author)

  12. Model of reverse steam generator

    International Nuclear Information System (INIS)

    Malasek, V.; Manek, O.; Masek, V.; Riman, J.

    1987-01-01

    The claim of Czechoslovak discovery no. 239272 is a model designed for the verification of the properties of a reverse steam generator during the penetration of water, steam-water mixture or steam into liquid metal flowing inside the heat exchange tubes. The design may primarily be used for steam generators with a built-in inter-tube structure. The model is provided with several injection devices configured in different heat exchange tubes, spaced at different distances along the model axis. The design consists in that between the pressure and the circumferential casings there are transverse partitions and that in one chamber consisting of the circumferential casings, pressure casing and two adjoining partitions there is only one passage of the injection device through the inter-tube space. (Z.M.). 1 fig

  13. Steam generator thermal-hydraulics

    International Nuclear Information System (INIS)

    Inch, W.W.; Scott, D.A.; Carver, M.B.

    1980-01-01

    This paper discusses a code for detailed numerical modelling of steam generator thermal-hydraulics, and describes related experimental programs designed to promote in-depth understanding of three-dimensional two-phase flow. (auth)

  14. Evaluation of steam and soil solarization for Meloidogyne arenaria control in Florida floriculture crops

    Science.gov (United States)

    Steam and soil solarization were investigated for control of the root-knot nematode Meloidogyne arenaria in two years of field trials on a commercial flower farm in Florida. The objective was to determine if pre-plant steam treatments in combination with solarization, or solarization alone effective...

  15. French steam generator design developments

    International Nuclear Information System (INIS)

    Ginier, R.; Campan, J.L.; Pontier, M.; Leridon, A.; Remond, A.; Castello, G.; Holcblat, A.; Paurobally, H.

    1986-01-01

    From the outset of the French nuclear power program, a significant R and D effort has been invested in improvement of the design and operation of Pressurized Water Reactors including a special committment to improving steam generators. The steam generator enhancement program has spawned a wide variety of specific R and D resources, e.g., low temperature hydraulic models for investigation of areas with single-phase flow, and freon-filled models for simulation of areas of steam generators experiencing two-phase flow (tube bundles and moisture separators). For the moisture separators, a large scale research program using freon-filled models and highly sophisticated instrumentation was used. Tests at reactor sites during startup of both 900 MWe and 1300 MWe have been used to validate the assumptions made on the basis of loop tests. These tests also demonstrated the validity of using freon to simulate two-phase flow conditions. The wealth of knowledge accumulated by the steam generator R and D program has been used to develop a new design of steam generators for the N4 plants. The current R and D effort is aimed at qualifying the N4 steam generator model and developing more comprehensive models. One prong of the R and D effort is the Megeve program. Megeve is a 25 MW steam generator which simulates operating conditions of the N4 model. The other prong is Clotaire, a freon-filled steam generator model which will be used to qualify thermal/hydraulic design codes used for multidimensional calculations for design of tube bundles

  16. Research program plan: steam generators

    International Nuclear Information System (INIS)

    Muscara, J.; Serpan, C.Z. Jr.

    1985-07-01

    This document presents a plan for research in Steam Generators to be performed by the Materials Engineering Branch, MEBR, Division of Engineering Technology, (EDET), Office of Nuclear Regulatory Research. It is one of four plans describing the ongoing research in the corresponding areas of MEBR activity. In order to answer the questions posed, the Steam Generator Program has been organized with the three elements of non-destructive examination; mechanical integrity testing; and corrosion, cleaning and decontamination

  17. Options for Steam Generator Decommissioning

    International Nuclear Information System (INIS)

    Krause, Gregor; Amcoff, Bjoern; Robinson, Joe

    2016-01-01

    Selecting the best option for decommissioning steam generators is a key consideration in preparing for decommissioning PWR nuclear power plants. Steam Generators represent a discrete waste stream of large, complex items that can lend themselves to a variety of options for handling, treatment, recycling and disposal. Studsvik has significant experience in processing full size Steam Generators at its metal recycling facility in Sweden, and this paper will introduce the Studsvik steam generator treatment concept and the results achieved to date across a number of projects. The paper will outline the important parameters needed at an early stage to assess options and to help consider the balance between off-site and on-site treatment solutions, and the role of prior decontamination techniques. The paper also outlines the use of feasibility studies and demonstration projects that have been used to help customers prepare for decommissioning. The paper discusses physical, radiological and operational history data, Pro and Contra factors for on- and off-site treatment, the role of chemical decontamination prior to treatment, planning for off-site shipments as well as Studsvik experience This paper has an original focus upon the coming challenges of steam generator decommissioning and potential external treatment capacity constraints in the medium term. It also focuses on the potential during operations or initial shut-down to develop robust plans for steam generator management. (authors)

  18. Southeast Regional Wastewater Treatment Plant Facilities Improvements Project and Geysers Effluent Pipeline Project. Final EIR/EIS

    International Nuclear Information System (INIS)

    1994-01-01

    On May 26, 1994, the Lake County Sanitation District and the US Bureau of Land Management released for public review a Draft Environmental Impact Report/Environmental Impact Statement (EIR/EIS) on the proposed Southeast Regional Wastewater Treatment Plant Facilities Improvements Project and Geysers Effluent Pipeline Project. A minimum 45-day review and comment period began on that date and notices were published in the Federal Register. The public review and comment period closed on July 26, 1994. Public hearings on the Draft EIMIS were held in Lakeport, CA, on June 30 and July 14, 1994. The first part of this document contains copies of the written comments submitted on the Draft EIR/EIS. It also contains summary paraphrased comments of the public hearings. The second part of this document contains responses to the comments

  19. Initiation of geyser during the resettlement of cryogenic liquid under impulsive reverse gravity acceleration in microgravity environment

    Science.gov (United States)

    Hung, R. J.; Shyu, K. L.

    1991-01-01

    The requirement to settle or to position liquid fluid over the outlet end of spacecraft propellant tank prior to main engine restart poses a microgravity fluid behavior problem. Resettlement or reorientation of liquid propellant can be accomplished by providing optimal acceleration to the spacecraft such that the propellant is reoriented over the tank outlet without any vapor entrainment, any excessive geysering, or any other undesirable fluid motion for the space fluid management under microgravity environment. The purpose of present study is to investigate most efficient technique for propellant resettling through the minimization of propellant usage and weight penalties. Comparison between the constant reverse gravity acceleration and impulsive reverse gravity acceleration to be used for the activation of propellant resettlement, it shows that impulsive reverse gravity thrust is superior to constant reverse gravity thrust for liquid reorientation in a reduced gravity environment.

  20. Site Specific Probabilistic Seismic Hazard and Risk Analysis for Surrounding Communities of The Geysers Geothermal Development Area

    Science.gov (United States)

    Miah, M.; Hutchings, L. J.; Savy, J. B.

    2014-12-01

    We conduct a probabilistic seismic hazard and risk analysis from induced and tectonic earthquakes for a 50 km radius area centered on The Geysers, California and for the next ten years. We calculate hazard with both a conventional and physics-based approach. We estimate site specific hazard. We convert hazard to risk of nuisance and damage to structures per year and map the risk. For the conventional PSHA we assume the past ten years is indicative of hazard for the next ten years from Mnoise. Then, we interpolate within each geologic unit in finely gridded points. All grid points within a unit are weighted by distance from each data collection point. The entire process is repeated for all of the other types of geologic units until the entire area is gridded and assigned a hazard value for every grid points. We found that nuisance and damage risks calculated by both conventional and physics-based approaches provided almost identical results. This is very surprising since they were calculated by completely independent means. The conventional approach used the actual catalog of the past ten years of earthquakes to estimate the hazard for the next ten year. While the physics-based approach used geotechnical modeling to calculate the catalog for the next ten years. Similarly, for the conventional PSHA, we utilized attenuation relations from past earthquakes recorded at the Geysers to translate the ground motion from the source to the site. While for the physics-based approach we calculated ground motion from simulation of actual earthquake rupture. Finally, the source of the earthquakes was the actual source for the conventional PSHA. While, we assumed random fractures for the physics-based approach. From all this, we consider the calculation of the conventional approach, based on actual data, to validate the physics-based approach used.

  1. Vibration Analysis for Steam Dryer of APR1400 Steam Generator

    Energy Technology Data Exchange (ETDEWEB)

    Han, Sung-heum; Ko, Doyoung [KHNP CRI, Daejeon (Korea, Republic of); Cho, Minki [Doosan Heavy Industry, Changwon (Korea, Republic of)

    2016-10-15

    This paper is related to comprehensive vibration assessment program for APR1400 steam generator internals. According to U.S. Nuclear Regulatory Commission, Regulatory Guide 1.20 (Rev.3, March 2007), we conducted vibration analysis for a steam dryer as the second steam separator of steam generator internals. The vibration analysis was performed at the 100 % power operating condition as the normal operation condition. The random hydraulic loads were calculated by the computational fluid dynamics and the structural responses were predicted by power spectral density analysis for the probabilistic method. In order to meet the recently revised U.S. NRC RG 1.20 Rev.3, the CVAP against the potential adverse flow effects in APR1400 SG internals should be performed. This study conducted the vibration response analysis for the SG steam dryer as the second moisture separator at the 100% power condition, and evaluated the structural integrity. The predicted alternating stress intensities were evaluated to have more than 17.78 times fatigue margin compared to the endurance limit.

  2. Design of SMART steam generator cassette

    International Nuclear Information System (INIS)

    Kim, Y. W.; Kim, J. I.; Jang, M. H.

    2001-01-01

    Basic design development for the steam generator to be installed in the integral reactor SMART has been performed. Optimization of the steam generator shape, determination of the basic dimension and confirmation of the structural strength have been carried out. Individual steam generator cassette can be replaced in the optimized design concept of steam generator. Shape design of the steam generator cassette has been done on the computer based on 3-D CAE strategy. The structural integrity of the developed steam generator was investigated by performing the dynamic analysis for the steam generator cassette, flow induced vibration analysis for the tube bundle, and the thermo-mechanical analysis for the module header and tube. As for the manufacturing of steam generator, the numerical and the experimental simulation have been carried to control the amount of spring back and to eliminate residual stress. SMART steam generator cassette was developed by a sequential research of the aforementioned activities

  3. A study on the steam generator data base and the evaluation of chemical environment

    International Nuclear Information System (INIS)

    Yang, Kyung Rin; Yoo, Je Hyoo; Lee, Eun He; Hong, Kwang Pum

    1990-01-01

    In order to make steam generator data base, the basic plant information and water quality control data on the steam generators of the PWR nuclear power plant operating in the world have been collected by EPRI. In this project, the basic information and water quality control data of the domestic PWR nuclear power plants were collected to make steam generator data base on the basic of the EPRI format table, and the computerization of them was performed. Also, the technical evaluation of chemical environments on steam generator of the Kori 2 plant chemists. Workers and researchers working at the research institute and universities and so on. Especially, it is able to be used as a basic plant information in order to develop an artificial intellegence development system in the field on the technical development of the chemical environment. The scope and content of the project are following. The data base on the basic information data in domestic PWR plant. The steam generator data base on water quality control data. The evaluation on the chemical environment in the steam generators of the Kori 2 plant. From previous data, it is concluded as follows. The basic plant information on the domestic PWR power plant were computerized. The steam generator data base were made on the basis of EPRI format table. The chemical environment of the internal steam generators could be estimated from the analytical evaluation of water quality control data of the steam generator blowdown. (author)

  4. A three-dimensional laboratory steam injection model allowing in situ saturation measurements

    Energy Technology Data Exchange (ETDEWEB)

    Demiral, B.M.R.; Pettit, P.A.; Castanier, L.M.; Brigham, W.E.

    1992-08-01

    The CT imaging technique together with temperature and pressure measurements were used to follow the steam propagation during steam and steam foam injection experiments in a three dimensional laboratory steam injection model. The advantages and disadvantages of different geometries were examined to find out which could best represent radial and gravity override flows and also fit the dimensions of the scanning field of the CT scanner. During experiments, steam was injected continuously at a constant rate into the water saturated model and CT scans were taken at six different cross sections of the model. Pressure and temperature data were collected with time at three different levels in the model. During steam injection experiments, the saturations obtained by CT matched well with the temperature data. That is, the steam override as observed by temperature data was also clearly seen on the CT pictures. During the runs where foam was present, the saturation distributions obtained from CT pictures showed a piston like displacement. However, the temperature distributions were different depending on the type of steam foam process used. The results clearly show that the pressure/temperature data alone are not sufficient to study steam foam in the presence of non-condensible gas.

  5. Prediction of localized flow velocities and turbulence in a PWR steam generator: Final report

    International Nuclear Information System (INIS)

    Stuhmiller, J.H.

    1988-05-01

    The Steam Generator Project Office (SGPO) of the Steam Generator Owners Group and Electric Power Research Institute has developed a methodology for prediction of steam generator tube buffeting and associated material wear. Turbulent buffeting of steam generator tubes causes low amplitude vibratory response which results in fretting wear at support locations. Concerns raised at the Zion Nuclear Power Plant regarding the useful life of their steam generators prompted this study, in which the SGPO methodology is applied to analysis of the Westinghouse Model 51 steam generator. The specific intent of this project was to calculate turbulent buffeting forces within the tube bank of an operating Model 51 steam generator as a first step in the overall SGPO tube vibration and wear prediction strategy. Attention is focused on flow in the vicinity of anti-vibration bars (U-bend region) and on the flow that leaves the downcomer to impact against peripheral tubes. Other projects utilized the buffeting forces calculated here to determine tube vibratory response, tube-support plate impact statistics, and material wear rates. Besides successfully calculating hydraulic buffeting loads within the tube bank, the present project has enhanced the SGPO methodology and has identified hitherto unnoticed flow phenomena that occur in the steam generator. Experiments have also been carried out to validate numerical computations of the steam generator flow field

  6. Isotopic composition of steam samples from Lanzarote, Canary Islands

    Energy Technology Data Exchange (ETDEWEB)

    Arana, V. (CSIC, Madrid); Panichi, C.

    1974-12-01

    The isotopic analysis of the steam samples collected in the geothermal area of Lanzarote show that the values of delta D are practically constant, and those of delta /sup 18/O range in a shift of 17 /sup 0///sub 00/ reaching a maximum of +14.7 /sup 0///sub 00/ versus SMOW, this last value being the highest found in steam samples. This composition can be explained as a consequence of the isotopic exchange at high temperature between limestones and a mixture of marine and local meteoric waters. This interpretation agrees with previous geological and geophysical studies which consider that a promising geothermal field could exist in Lanzarote. (auth)

  7. Maintenance and plugging technology for CANDU steam generator tubing

    International Nuclear Information System (INIS)

    Prince, J.; Nicholson, A.; Hare, J.; McGoey, L.; Stafford, T.; Gowthorpe, P.

    2006-01-01

    In order to keep aging steam generators in service and to successfully manage the life of these critical components, the capability must exist to perform tube plugging and other complex maintenance activities in-situ. In the early days of CANDU steam generator operation, the only option was to perform these activities manually, which had inherent safety and quality risks. The challenge was to be able to perform these activities remotely thus eliminating some of the confined space and radiological exposure risks. The additional challenge was to develop equipment and techniques which would result in significantly improved quality, particularly for the completed plug welds which would be returned to service. Over the past fifteen years, this technology has matured and has produced remarkable results in field application. Some 14000 tube plugs have been successfully installed to date using automated plugging techniques. This paper presents an overview of the development of techniques available to utilities for steam generator tube plugging as well as some highlights of other steam generator tube maintenance activities such as primary side tube removal and tube end damage repair. Aspects covered in the paper include plug and procedure development, automated equipment and manipulators for tool deployment, process controls and personnel requirements. Recently, the steam generator tube plugging performed by OPG has been incorporated into a formal quality program under the requirements of ASME NCA 4000. An overview of the quality program will be presented and details of some of the important aspects of the quality program will be discussed. (author)

  8. Maintaining steam/condensate lines

    International Nuclear Information System (INIS)

    Russum, S.A.

    1992-01-01

    Steam and condensate systems must be maintained with the same diligence as the boiler itself. Unfortunately, they often are not. The water treatment program, critical to keeping the boiler at peak efficiency and optimizing operating life, should not stop with the boiler. The program must encompass the steam and condensate system as well. A properly maintained condensate system maximizes condensate recovery, which is a cost-free energy source. The fuel needed to turn the boiler feedwater into steam has already been provided. Returning the condensate allows a significant portion of that fuel cost to be recouped. Condensate has a high heat content. Condensate is a readily available, economical feedwater source. Properly treated, it is very pure. Condensate improves feedwater quality and reduces makeup water demand and pretreatment costs. Higher quality feedwater means more reliable boiler operation

  9. Steam generator operation and maintenance

    International Nuclear Information System (INIS)

    Lee, C.K.

    2004-01-01

    Corrosion of steam generator tube has resulted in the need for extensive repair and replacement of steam generators. Over the past two decades, steam generator problems in the United States were viewed to be one of the most significant contributor to lost generation in operating PWR plants. When the SGOG-I (Steam Generator Owners Groups) was formed in early 1977, denting was responsible for almost 90% of the tube plugging. By the end of 1982, this figure was reduced to less than 2%. During the existence of SGOG-II (from 1982 to 1986), IGA/SCC (lntergranular Attack/Stress Corrosion Cracking) in the tube sheet, primary side SCC, pitting, and fretting surfaced as the primary causes of tube degradation. Although significant process has been made with wastage and denting, the utilities experience shows that the percentage of reactors plugging tubes and the percentage of tubes being plugged each year has remained relatively constant. The diversity of the damage mechanisms means that no one solution is likely to resolve all problems. The task of maintaining steam generator integrity continues to be formidable and challenging. As the older problems were brought under control, many new problems emerged. SGOG-II (Steam Generator Owners Group program from 1982 to 1986) has focused on these problem areas such as tube stress corrosion cracking (SCC) and intergranular attack (IGA) in the open tube sheet crevice, primary side tube cracking, pitting in the lower span, and tube fretting in preheated section and anti-vibration bar (AVB) locations. Primary Water Stress Corrosion Cracking (PWSCC) in the tube to tubesheet roll transition has been a wide spread problem in the Recirculation Steam Generators (RSG) during this period. Although significant progress has been made in resolving this problem, considerable work still remains. One typical problem in the Once Through Steam Generator (OTSG) was the tube support plate broached hole fouling which affects the OTSG steam generating

  10. Water box for steam generator

    International Nuclear Information System (INIS)

    Lecomte, Robert; Viaud, Michel.

    1975-01-01

    This invention relates to a water box for connecting an assembly composed of a vertical steam generator and a vertical pump to the vessel of the nuclear reactor, the assembly forming the primary cooling system of a pressurised water reactor. This invention makes it easy to dismantle the pump on the water box without significant loss of water in the primary cooling system of the reactor and particularly without it being necessary to drain the water contained in the steam generator beforehand. It makes it possible to shorten the time required for dismantling the primary pump in order to service or repair it and makes dismantling safer in that the dismantling does not involve draining the steam generator and therefore the critical storage of a large amount of cooling water that has been in contact with the fuel assemblies of the nuclear reactor core [fr

  11. Study group meeting on steam generators for LMFBR's. Summary report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1975-07-01

    The Meeting organised by IAEA international working group on fast reactors which considered that the subject of sodium heated steam generators was a topic which needed study by the experts of several disciplines. For example: people who design such steam generators, specialists in the field of sodium water reactions, experts in material and water chemistry and members of the utilities who would be the customers for such units. Besides the exchange of large amount of information, it was considered that further special studies were necessary for the following subjects: materials; maintenance and repair; operating procedures and control of steam generators. A separate study of sodium-water reactions was recommended considering the safety aspects related to large water leakage and economic advantage of possible detection and protection against small water leaks.

  12. Steam injection and enhanced bioremediation of heavy fuel oil contamination

    International Nuclear Information System (INIS)

    Dablow, J.; Hicks, R.; Cacciatore, D.

    1995-01-01

    Steam injection has been shown to be successful in remediating sites impacted by heavy fuel oils. Field demonstrations at both pilot and full scale have removed No. 2 diesel fuel and Navy Special Fuel Oil (No. 5 fuel oil) from impacted soils. Removal mechanisms include enhanced volatilization of vapor- and adsorbed-phase contaminants and enhanced mobility due to decreased viscosity and associated residual saturation of separate- and adsorbed-phase contaminants. Laboratory studies have shown that indigenous biologic populations are significantly reduced, but are not eliminated by steam injection operations. Populations were readily reestablished by augmentation with nutrients. This suggests that biodegradation enhanced by warm, moist, oxygenated environments can be expected to further reduce concentrations of contaminants following cessation of steam injection operations

  13. Steam Generator Group Project. Task 6. Channel head decontamination

    International Nuclear Information System (INIS)

    Allen, R.P.; Clark, R.L.; Reece, W.D.

    1984-08-01

    The Steam Generator Group Project utilizes a retired-from-service pressurized-water-reactor steam generator as a test bed and source of specimens for research. An important preparatory step to primary side research activities was reduction of the radiation field in the steam generator channel head. This task report describes the channel head decontamination activities. Though not a programmatic research objective it was judged beneficial to explore the use of dilute reagent chemical decontamination techniques. These techniques presented potential for reduced personnel exposure and reduced secondary radwaste generation, over currently used abrasive blasting techniques. Two techniques with extensive laboratory research and vendors prepared to offer commercial application were tested, one on either side of the channel head. As indicated in the report, both techniques accomplished similar decontamination objectives. Neither technique damaged the generator channel head or tubing materials, as applied. This report provides details of the decontamination operations. Application system and operating conditions are described

  14. Study group meeting on steam generators for LMFBR's. Summary report

    International Nuclear Information System (INIS)

    1975-07-01

    The Meeting organised by IAEA international working group on fast reactors which considered that the subject of sodium heated steam generators was a topic which needed study by the experts of several disciplines. For example: people who design such steam generators, specialists in the field of sodium water reactions, experts in material and water chemistry and members of the utilities who would be the customers for such units. Besides the exchange of large amount of information, it was considered that further special studies were necessary for the following subjects: materials; maintenance and repair; operating procedures and control of steam generators. A separate study of sodium-water reactions was recommended considering the safety aspects related to large water leakage and economic advantage of possible detection and protection against small water leaks

  15. Study of liquid and steam tracers at the Maritaro - La Cumbre area of the Los Azufres geothermal field, Mich.; Estudio con trazadores de liquido y vapor en la zona Maritaro - La Cumbre del campo geotermico de Los Azufres, Mich.

    Energy Technology Data Exchange (ETDEWEB)

    Iglesias, Eduardo R [Instituto de Investigaciones Electricas, Cuernavaca, Morelos, (Mexico)]. E-mail: iglesias@iie.org.mx; Flores Armenta, Magaly; Quijano Leon, Jose Luis; Torres Rodriguez, Marco A [Comision Federal de Electricidad, Morelia, Michoacan (Mexico); Torres, Rodolfo J; Reyes Picasso, Neftali [Instituto de Investigaciones Electricas, Cuernavaca, Morelos, (Mexico)

    2008-01-15

    We ran two simultaneous tracer tests in the Maritaro-La Cumbre area of the Los Azufres geothermal field in Mexico. We wished to determine whether or not fluids injected in well Az-15 recharged the productive areas of six production wells and to estimate the fractions of injected fluid recovered in them, if any. Because only three of the wells produce water and all of them produce steam, two tracers were used, sulfur hexafluoride (SF{sub 6}) for the gas phase and 1,3,6 naphthalene trisulfonate (1,3,6-nts) for the liquid phase. All of the observation wells recorded SF{sub 6}, and the three water-producing wells recorded 1,3,6-nts, proving that fluids injected in well Az-15 do recharge the area of interest. When sampling was suspended, the three water-producing wells were still producing 1,3,6-nts at significant rates. The total recovery of 1,3,6-nts at wells Az-65D, Az-04 and Az-28, 279 days after injection when sampling was halted, were, respectively, 6.1%, 0.90% y 0.16%, for a total of 7.61%. We concluded that these quantities constitute the lower boundaries for the respective recovery factors. When sampling was halted, wells Az-65D, Az-66D and Az-30 were still producing some SF{sub 6} at lower rates, and the rest of the wells were no longer recording the gas phase tracer. The total recovery of SF{sub 6} at wells Az-65D, Az-04, Az-41, Az-30, Az-28 and Az-66D were, respectively, 4.82 e-02%, 1.37 e-03%, 1.48 e-03%, 6.38 e-04%, 1.38 e-03% y 4.31 e-04%, for a total of 5.35 e-02%. The liquid recharge occurred in orders of magnitude greater than the steam. [Spanish] Se efectuaron dos pruebas simultaneas en la zona Maritaro-La Cumbre del campo geotermico de Los Azufres, Mich., Mexico. Los objetivos de estas pruebas fueron determinar si la salmuera de desecho inyectada en el pozo Az-15 recarga las zonas de alimentacion de seis pozos productores designados por CFE, y estimar que fraccion de lo inyectado recarga dichos pozos productores. Debido a que solo tres de los pozos

  16. Predicting steam generator crevice chemistry

    International Nuclear Information System (INIS)

    Burton, G.; Strati, G.

    2006-01-01

    'Full text:' Corrosion of steam cycle components produces insoluble material, mostly iron oxides, that are transported to the steam generator (SG) via the feedwater and deposited on internal surfaces such as the tubes, tube support plates and the tubesheet. The build up of these corrosion products over time can lead to regions of restricted flow with water chemistry that may be significantly different, and potentially more corrosive to SG tube material, than the bulk steam generator water chemistry. The aim of the present work is to predict SG crevice chemistry using experimentation and modelling as part of AECL's overall strategy for steam generator life management. Hideout-return experiments are performed under CANDU steam generator conditions to assess the accumulation of impurities in hideout, and return from, model crevices. The results are used to validate the ChemSolv model that predicts steam generator crevice impurity concentrations, and high temperature pH, based on process parameters (e.g., heat flux, primary side temperature) and blowdown water chemistry. The model has been incorporated into ChemAND, AECL's system health monitoring software for chemistry monitoring, analysis and diagnostics that has been installed at two domestic and one international CANDU station. ChemAND provides the station chemists with the only method to predict SG crevice chemistry. In one recent application, the software has been used to evaluate the crevice chemistry based on the elevated, but balanced, SG bulk water impurity concentrations present during reactor startup, in order to reduce hold times. The present paper will describe recent hideout-return experiments that are used for the validation of the ChemSolv model, station experience using the software, and improvements to predict the crevice electrochemical potential that will permit station staff to ensure that the SG tubes are in the 'safe operating zone' predicted by Lu (AECL). (author)

  17. Nuclear reactor steam depressurization valve

    International Nuclear Information System (INIS)

    Moore, G.L.

    1991-01-01

    This patent describes improvement in a nuclear reactor plant, an improved steam depressurization valve positioned intermediate along a steam discharge pipe for controlling the venting of steam pressure from the reactor through the pipe. The improvement comprises: a housing including a domed cover forming a chamber and having a partition plate dividing the chamber into a fluid pressure activation compartment and a steam flow control compartment, the valve housing being provided with an inlet connection and an outlet connection in the steam flow control compartment, and a fluid duct in communication with a source of fluid pressure for operating the valve; a valve set mounted within the fluid flow control compartment comprising a cylindrical section surrounding the inlet connection with one end adjoining the connection and having a radially projecting flange at the other end with a contoured extended valve sealing flange provided with an annular valve sealing member, and a valve cylinder traversing the partition plate and reciprocally movable within an opening in the partition plate with one terminal and extending into the fluid pressure activation compartment and the other terminal end extending into the steam flow control compartment coaxially aligned with the valve seat surrounding the inlet connection, the valve cylinder being surrounded by two bellow fluid seals and provided with guides to inhibit lateral movement, an end of the valve cylinder extending into the fluid flow control compartment having a radially projecting flange substantially conterminous with the valve seat flange and having a contoured surface facing and complimentary to the contoured valve seating surface whereby the two contoured valve surfaces can meet in matching relationship, thus providing a pressure actuated reciprocatable valve member for making closing contact with the valve seat and withdrawing therefrom for opening fluid flow through the valve

  18. Nuclear steam generator tubesheet shield

    International Nuclear Information System (INIS)

    Nickerson, J.H.D.; Ruhe, A.

    1982-01-01

    The invention involves improvements to a nuclear steam generator of the type in which a plurality of U-shaped tubes are connected at opposite ends to a tubesheet and extend between inlet and outlet chambers, with the steam generator including an integral preheater zone adjacent to the downflow legs of the U-shaped tubes. The improvement is a thermal shield disposed adjacent to an upper face of the tubesheet within the preheater zone, the shield including ductile cladding material applied directly to the upper face of the tubesheet, with the downflow legs of the U-shaped tubes extending through the cladding into the tubesheet

  19. Steam turbines for PWR stations

    International Nuclear Information System (INIS)

    Muscroft, J.

    1989-01-01

    The thermodynamic cycle requirements and mechanical design features applying to modern GEC 3000 rev/min steam turbines for pressurised water reactor power stations are reviewed. The most recent developments include machines of 630 MW and 985 MW output which are currently under construction. The importance of service experience with nuclear wet steam turbines associated with a variety of types of water cooled reactor and its relevance to the design of modern 3000 rev/min turbines for pressurised water reactor applications is emphasised. (author)

  20. Double wall steam generator tubing

    International Nuclear Information System (INIS)

    Padden, T.R.; Uber, C.F.

    1983-01-01

    Double-walled steam generator tubing for the steam generators of a liquid metal cooled fast breeder reactor prevents sliding between the surfaces due to a mechanical interlock. Forces resulting from differential thermal expansion between the outer tube and the inner tube are insufficient in magnitude to cause shearing of base metal. The interlock is formed by jointly drawing the tubing, with the inside wall of the outer tube being already formed with grooves. The drawing causes the outer wall of the inner tube to form corrugations locking with the grooves. (author)

  1. Steam reforming of light oxygenates

    DEFF Research Database (Denmark)

    Trane-Restrup, Rasmus; Resasco, Daniel E; Jensen, Anker Degn

    2013-01-01

    Steam reforming (SR) of ethanol, acetic acid, acetone, acetol, 1-propanol, and propanal has been investigated over Ni/MgAl2O4 at temperatures between 400 and 700 degrees C and at a steam-to-carbon-ratio (S/C) of 6. The yield of H-2 and conversion increased with temperature, while the yield of by-...... of CH4. Significant deactivation of the catalyst was observed for all of the compounds and was mainly due to carbon formation. The carbon formation was highest for alcohols due to a high formation of olefins, which are potent coke precursors....

  2. Steam Digest 2001: Office of Industrial Technologies

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2002-01-01

    Steam Digest 2001 chronicles Best Practices Program's contributions to the industrial trade press for 2001, and presents articles that cover technical, financial and managerial aspects of steam optimization.

  3. Vapor generator steam drum spray heat

    International Nuclear Information System (INIS)

    Fasnacht, F.A. Jr.

    1978-01-01

    A typical embodiment of the invention provides a combination feedwater and cooldown water spray head that is centrally disposed in the lower portion of a nuclear power plant steam drum. This structure not only discharges the feedwater in the hottest part of the steam drum, but also increases the time required for the feedwater to reach the steam drum shell, thereby further increasing the feedwater temperature before it contacts the shell surface, thus reducing thermal shock to the steam drum structure

  4. Steam turbines for nuclear power plants

    International Nuclear Information System (INIS)

    Kosyak, Yu.F.

    1978-01-01

    Considered are the peculiarities of the design and operation of steam turbines, condensers and supplementary equipment of steam turbines for nuclear power plants; described are the processes of steam flow in humid-steam turbines, calculation and selection principles of main parameters of heat lines. Designs of the turbines installed at the Charkov turbine plant are described in detail as well as of those developed by leading foreign turbobuilding firms

  5. Water-chemistry data for selected springs, geysers, and streams in Yellowstone National Park, Wyoming, 2006-2008

    Science.gov (United States)

    Ball, James W.; McMleskey, R. Blaine; Nordstrom, D. Kirk

    2010-01-01

    Water analyses are reported for 104 samples collected from numerous thermal and non-thermal features in Yellowstone National Park (YNP) during 2006-2008. Water samples were collected and analyzed for major and trace constituents from 10 areas of YNP including Apollinaris Spring and Nymphy Creek along the Norris-Mammoth corridor, Beryl Spring in Gibbon Canyon, Norris Geyser Basin, Lower Geyser Basin, Crater Hills, the Geyser Springs Group, Nez Perce Creek, Rabbit Creek, the Mud Volcano area, and Washburn Hot Springs. These water samples were collected and analyzed as part of research investigations in YNP on arsenic, antimony, iron, nitrogen, and sulfur redox species in hot springs and overflow drainages, and the occurrence and distribution of dissolved mercury. Most samples were analyzed for major cations and anions, trace metals, redox species of antimony, arsenic, iron, nitrogen, and sulfur, and isotopes of hydrogen and oxygen. Analyses were performed at the sampling site, in an on-site mobile laboratory vehicle, or later in a U.S. Geological Survey laboratory, depending on stability of the constituent and whether it could be preserved effectively. Water samples were filtered and preserved on-site. Water temperature, specific conductance, pH, emf (electromotive force or electrical potential), and dissolved hydrogen sulfide were measured on-site at the time of sampling. Dissolved hydrogen sulfide was measured a few to several hours after sample collection by ion-specific electrode on samples preserved on-site. Acidity was determined by titration, usually within a few days of sample collection. Alkalinity was determined by titration within 1 to 2 weeks of sample collection. Concentrations of thiosulfate and polythionate were determined as soon as possible (generally a few to several hours after sample collection) by ion chromatography in an on-site mobile laboratory vehicle. Total dissolved iron and ferrous iron concentrations often were measured on-site in the

  6. Passive system with steam-water injector for emergency supply of NPP steam generators

    International Nuclear Information System (INIS)

    Il'chenko, A.G.; Strakhov, A.N.; Magnitskij, D.N.

    2009-01-01

    The calculation results of reliability indicators of emergency power supply system and emergency feed-water supply system of serial WWER-1000 unit are presented. To ensure safe water supply to steam generators during station blackout it was suggested using additional passive emergency feed-water system with a steam-water injector working on steam generators dump steam. Calculated analysis of steam-water injector operating capacity was conducted at variable parameters of steam at the entrance to injector, corresponding to various moments of time from the beginning of steam-and-water damping [ru

  7. Parametric study for horizontal steam generator modelling

    Energy Technology Data Exchange (ETDEWEB)

    Ovtcharova, I. [Energoproekt, Sofia (Bulgaria)

    1995-12-31

    In the presentation some of the calculated results of horizontal steam generator PGV - 440 modelling with RELAP5/Mod3 are described. Two nodalization schemes have been used with different components in the steam dome. A study of parameters variation on the steam generator work and calculated results is made in cases with separator and branch.

  8. STEAM DALAM PEMBUATAN PAKAN UNTUK KOMODITAS AKUAKULTUR

    Directory of Open Access Journals (Sweden)

    Sukarman Sukarman

    2010-12-01

    Full Text Available Kualitas fisik pakan (pelet untuk hewan akuakultur sangat penting, karena akan dimasukkan ke dalam air dan diharapkan tidak banyak mencemari lingkungan. Salah satu faktor yang berpengaruh dalam menjaga kualitas fisik pakan adalah penambahan dan pengaturan steam pada saat proses pembuatan pelet. Steam adalah aliran gas yang dihasilkan oleh air pada saat mendidih. Steam dibagi menjadi 3 jenis yaitu steam basah, saturated steam, dan superheated steam. Steam yang digunakan dalam proses pembuatan pelet adalah saturated steam. Pengaruh penambahan steam pada kualitas pelet bisa mencapai 20%. Penambahan steam dengan jumlah dan kualitas yang tepat akan menghasilkan pelet berkualitas. Sedangkan jika pengaturan dan penambahannya tidak tepat, maka kualitas fisik pelet akan rendah dan kemungkinan bisa merusak kandungan nutrisi seperti vitamin dan protein. Penambahan steam yang benar bisa dilakukan di dalam kondisioner dengan mengatur retention time, sudut kemiringan paddle conditioner, kecepatan putaran bearing dan menjaga kualitas steam dari mesin boiler sampai dengan kondisioner.

  9. Parametric study for horizontal steam generator modelling

    Energy Technology Data Exchange (ETDEWEB)

    Ovtcharova, I [Energoproekt, Sofia (Bulgaria)

    1996-12-31

    In the presentation some of the calculated results of horizontal steam generator PGV - 440 modelling with RELAP5/Mod3 are described. Two nodalization schemes have been used with different components in the steam dome. A study of parameters variation on the steam generator work and calculated results is made in cases with separator and branch.

  10. Hybrid preheat/recirculating steam generator

    International Nuclear Information System (INIS)

    Lilly, G.P.

    1985-01-01

    The patent describes a hybrid preheat/recirculating steam generator for nuclear power plants. The steam generator utilizes recirculated liquid to preheat incoming liquid. In addition, the steam generator incorporates a divider so as to limit the amount of recirculating water mixed with the feedwater. (U.K.)

  11. BWR Steam Dryer Alternating Stress Assessment Procedures

    Energy Technology Data Exchange (ETDEWEB)

    Morante, R. J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Hambric, S. A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ziada, S. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-12-01

    This report presents an overview of Boiling Water Reactor (BWR) steam dryer design; the fatigue cracking failures that occurred at the Quad Cities (QC) plants and their root causes; a history of BWR Extended Power Uprates (EPUs) in the USA; and a discussion of steam dryer modifications/replacements, alternating stress mechanisms on steam dryers, and structural integrity evaluations (static and alternating stress).

  12. Materials Performance in USC Steam

    Energy Technology Data Exchange (ETDEWEB)

    G. R. Holcomb, P. Wang, P. D. Jablonski, and J. A. Hawk

    2010-05-01

    The proposed steam inlet temperature in the Advanced Ultra Supercritical (A-USC) steam turbine is high enough (760 °C) that traditional turbine casing and valve body materials such as ferritic/martensitic steels will not suffice due to temperature limitations of this class of materials. Cast versions of several traditionally wrought Ni-based superalloys were evaluated for use as casing or valve components for the next generation of industrial steam turbines. The full size castings are substantial: 2-5,000 kg each half and on the order of 100 cm thick. Experimental castings were quite a bit smaller, but section size was retained and cooling rate controlled to produce equivalent microstructures. A multi-step homogenization heat treatment was developed to better deploy the alloy constituents. The most successful of these cast alloys in terms of creep strength (Haynes 263, Haynes 282, and Nimonic 105) were subsequently evaluated by characterizing their microstructure as well as their steam oxidation resistance (at 760 and 800 °C).

  13. The STEAM behind the Scenes

    Science.gov (United States)

    Smith, Carmen Petrick; King, Barbara; González, Diana

    2015-01-01

    There is a growing need for STEAM-based (Science, Technology, Engineering, Arts, and Mathematics) knowledge and skills across a wide range of professions (Brazell 2013). Yet students often fail to see the usefulness of mathematics beyond the classroom (Kloosterman, Raymond, and Emenaker 1996), and they do not regularly make connections between…

  14. Technical diagnostics of steam turbines

    International Nuclear Information System (INIS)

    Vlckova, B.; Drahy, J.

    1987-01-01

    This paper deals with practical experience in application of technical diagnostics methods to steam turbines, in particular using pedestal and shaft vibration measurements as well as estimation of bearing metal temperature and ultrasound emission signals. An estimation of effectiveness of the diagnostics methods used is given on the basis of experimental investigations made on a 30-MW turbine. (author)

  15. Severity parameters for steam cracking

    NARCIS (Netherlands)

    Golombok, M.; Bijl, J.L.M.; Kornegoor, M.

    2001-01-01

    There are several ways to measure severity in steam cracking which are all a function of residence time, temperature, and pressure. Many measures of severity are not practicable for experimental purposes. Our experimental study shows that methane make is the best measure of severity because it is an

  16. Nuclear process steam for industry

    International Nuclear Information System (INIS)

    Seddon, W.A.

    1981-11-01

    A joint industrial survey funded by the Bruce County Council, the Ontario Energy Corporation and Atomic Energy of Canada Limited was carried out with the cooperation of Ontario Hydro and the Ontario Ministry of Industry and Tourism. Its objective was to identify and assess the future needs and interest of energy-intensive industries in an Industrial Energy Park adjacent to the Bruce Nuclear Power Development. The Energy Park would capitalize on the infrastructure of the existing CANDU reactors and Ontario Hydro's proven and unique capability to produce steam, as well as electricity, at a cost currently about half that from a comparable coal-fired station. Four industries with an integrated steam demand of some 1 x 10 6 lb/h were found to be prepared to consider seriously the use of nuclear steam. Their combined plants would involve a capital investment of over $200 million and provide jobs for 350-400 people. The high costs of transportation and the lack of docking facilities were considered to be the major drawbacks of the Bruce location. An indication of steam prices would be required for an over-all economic assessment

  17. Steam initiated hydrotalcite conversion coatings

    DEFF Research Database (Denmark)

    Zhou, Lingli; Friis, Henrik; Roefzaad, Melanie

    2018-01-01

    A facile process of exploiting high-temperature steam to deposit nvironmentally friendly hydrotalcite (HT) coatings on Al alloy 6060 was developed in a spray system. Scanning electron microscopy showed the formationf a continuous and conformal coating comprised of a compact mass of crystallites. ...

  18. Steam-water relative permeability

    Energy Technology Data Exchange (ETDEWEB)

    Ambusso, W.; Satik, C.; Home, R.N. [Stanford Univ., CA (United States)

    1997-12-31

    A set of relative permeability relations for simultaneous flow of steam and water in porous media have been measured in steady state experiments conducted under the conditions that eliminate most errors associated with saturation and pressure measurements. These relations show that the relative permeabilities for steam-water flow in porous media vary approximately linearly with saturation. This departure from the nitrogen/water behavior indicates that there are fundamental differences between steam/water and nitrogen/water flows. The saturations in these experiments were measured by using a high resolution X-ray computer tomography (CT) scanner. In addition the pressure gradients were obtained from the measurements of liquid phase pressure over the portions with flat saturation profiles. These two aspects constitute a major improvement in the experimental method compared to those used in the past. Comparison of the saturation profiles measured by the X-ray CT scanner during the experiments shows a good agreement with those predicted by numerical simulations. To obtain results that are applicable to general flow of steam and water in porous media similar experiments will be conducted at higher temperature and with porous rocks of different wetting characteristics and porosity distribution.

  19. Fretting-wear characteristics of steam generator tubes contacting with foreign object

    International Nuclear Information System (INIS)

    Jo, Jong Chull; Jhung, Myung Jo; Kim, Woong Sik; Kim, Hho Jung

    2003-01-01

    Fretting-wear characteristics of steam generator tubes contacting with foreign object has been investigated in this study. The operating steam generator shell-side flow field conditions are obtained from three-dimensional steam generator flow calculation using a well-validated steam generator thermal-hydraulic analysis computer code. Modal analyses are performed for the finite element modelings of tubes to get the natural frequency, corresponding mode shape and participation factor. The wear rate of a steam generator tube caused by foreign object is calculated using the Archard formula and the remaining life of the tube is predicted. In addition, the effects of internal pressure and flow velocity on the remaining life of the tube are discussed in this paper

  20. Fluidelastic instability analysis of steam generator U-tubes at antivibration bar-inactive modes

    International Nuclear Information System (INIS)

    Lee, S.K.; Jo, J.C.

    1995-01-01

    This paper presents the results of thermal-hydraulic and fluidelastic U-tube instability analyses performed for the vertical type pressurized water reactor (PWR) steam generator model being employed at Kori units 2, 3 and 4, and Yonggwang units 1 and 2 in Korea. The thermal-hydraulic analysis for providing the detailed three-dimensional two-phase flow field in the secondary side of the steam generator was accomplished using the ATHOS3 steam generator thermal-hydraulic analysis code. The UTVA2 code designed for calculating both the free vibration responses and fluidelastic stability ratio of a specific U-tube under consideration was used to assess the potential for fluidelastic instability of the steam generator U-tubes at various conditions of antivibration bar (AVB)-inactive modes. The results of the fluidelastic instability analysis were discussed in comparison with those obtained for the steam generator U-tubes at AVB-active mode

  1. Audio-based, unsupervised machine learning reveals cyclic changes in earthquake mechanisms in the Geysers geothermal field, California

    Science.gov (United States)

    Holtzman, B. K.; Paté, A.; Paisley, J.; Waldhauser, F.; Repetto, D.; Boschi, L.

    2017-12-01

    The earthquake process reflects complex interactions of stress, fracture and frictional properties. New machine learning methods reveal patterns in time-dependent spectral properties of seismic signals and enable identification of changes in faulting processes. Our methods are based closely on those developed for music information retrieval and voice recognition, using the spectrogram instead of the waveform directly. Unsupervised learning involves identification of patterns based on differences among signals without any additional information provided to the algorithm. Clustering of 46,000 earthquakes of $0.3

  2. Steam jet ejectors are examined automatically

    International Nuclear Information System (INIS)

    Lardiere, C.

    2013-01-01

    Steam jet ejectors are used in the nuclear industry particularly for the transfer of radioactive fluids. Their working is based on the Venturi effect and the conservation of energy. A steam ejector can be considered as a thermodynamical pump without mobile parts. The Descote enterprise manufactures a broad range of steam jet ejectors and the characterization and testing of the steam ejectors was made manually and empirically so far. A new test bench has been designed, the tests are led automatically and allow a more accurate characterization and optimization of the steam jet ejectors. (A.C.)

  3. Facility to separate water and steam

    International Nuclear Information System (INIS)

    Loesel, G.

    1977-01-01

    The water/steam mixture from the pressure vessel e.g. of a BWR is separated by means of centrifugal separators untilizing the natural separation of steam. The steam is supplied to a steam drying vessel and the water to a water collecting tank. These vessels may be combined to a common vessel or connected through additional pipes. From the water collecting tank, arranged below the steam dryer, a feedwater pipe runs back to the pressure vessel. By construction out of individual components cleaning, decontamination, and operating control are essentially simplified. (RW) 891 RW [de

  4. Cycle improvement for nuclear steam power plant

    International Nuclear Information System (INIS)

    Silvestri, G.J. Jr.

    1976-01-01

    A pressure-increasig ejector element is disposed in an extraction line intermediate to a high pressure turbine element and a feedwater heater. The ejector utilizes high pressure fluid from a reheater drain as the motive fluid to increase the pressure at which the extraction steam is introduced into the feedwater heater. The increase in pressure of the extraction steam entering the feedwater heater due to the steam passage through the ejector increases the heat exchange capability of the extraction steam thus increasing the overall steam power plant efficiency

  5. Radiocarbon dating of silica sinter deposits in shallow drill cores from the Upper Geyser Basin, Yellowstone National Park

    Science.gov (United States)

    Lowenstern, Jacob B.; Hurwitz, Shaul; McGeehin, John P.

    2016-01-01

    To explore the timing of hydrothermal activity at the Upper Geyser Basin (UGB) in Yellowstone National Park, we obtained seven new accelerator mass spectrometry (AMS) radiocarbon 14C ages of carbonaceous material trapped within siliceous sinter. Five samples came from depths of 15-152 cm within the Y-1 well, and two samples were from well Y-7 (depths of 24 cm and 122 cm). These two wells, at Black Sand and Biscuit Basins, respectively, were drilled in 1967 as part of a scientific drilling program by the U.S. Geological Survey (White et al., 1975). Even with samples as small as 15 g, we obtained sufficient carbonaceous material (a mixture of thermophilic mats, pollen, and charcoal) for the 14C analyses. Apparent time of deposition ranged from 3775 ± 25 and 2910 ± 30 14C years BP at the top of the cores to about 8000 years BP at the bottom. The dates are consistent with variable rates of sinter formation at individual sites within the UGB over the Holocene. On a basin-wide scale, though, these and other existing 14C dates hint that hydrothermal activity at the UGB may have been continuous throughout the Holocene.

  6. Horizontal steam generator thermal-hydraulics

    Energy Technology Data Exchange (ETDEWEB)

    Ubra, O. [SKODA Praha Company, Prague (Czechoslovakia); Doubek, M. [Czech Technical Univ., Prague (Czechoslovakia)

    1995-09-01

    Horizontal steam generators are typical components of nuclear power plants with pressure water reactor type VVER. Thermal-hydraulic behavior of horizontal steam generators is very different from the vertical U-tube steam generator, which has been extensively studied for several years. To contribute to the understanding of the horizontal steam generator thermal-hydraulics a computer program for 3-D steady state analysis of the PGV-1000 steam generator has been developed. By means of this computer program, a detailed thermal-hydraulic and thermodynamic study of the horizontal steam generator PGV-1000 has been carried out and a set of important steam generator characteristics has been obtained. The 3-D distribution of the void fraction and 3-D level profile as functions of load and secondary side pressure have been investigated and secondary side volumes and masses as functions of load and pressure have been evaluated. Some of the interesting results of calculations are presented in the paper.

  7. Steam atmosphere drying concepts using steam exhaust recompression

    Energy Technology Data Exchange (ETDEWEB)

    DiBella, F.A. (TECOGEN, Inc., Waltham, MA (United States))

    1992-08-01

    In the US industrial drying accounts for approximately 1.5 quads of energy use per year. Annual industrial dryer expenditures are estimated to be in the $500 million range. Industrial drying is a significant energy and monetary expense. For the thermal drying processes in which water is removed via evaporation from the feedstock, attempts have been made to reduce the consumption of energy using exhaust waste heat recovery techniques, improved dryer designs, or even the deployment of advanced mechanical dewatering techniques. Despite these efforts, it is obvious that a large amount of thermal energy is often still lost if the latent heat of evaporation from the evaporated water cannot be recovered and/or in some way be utilized as direct heat input into the dryer. Tecogen Inc. is conducting research and development on an industrial drying concept. That utilizes a directly or indirectly superheated steam cycle atmosphere with exhaust steam recompression to recover the latent heat in the exhaust that would otherwise be lost. This approach has the potential to save 55 percent of the energy required by a conventional air dryer. Other advantages to the industrial dryer user include: A 35-percent reduction in the yearly cost per kg[sub evap] to dry wet feedstock, Reduced airborne emissions, Reduced dry dust fire/explosion risks, Hot product not exposed to oxygen thus, the product quality is enhanced, Constant rate drying in steam atmosphere, Reduced dryer size and cost, Reduced dryer heat losses due to lower dryer inlet temperatures. Tecogen has projected that the steam atmosphere drying system is most suitable as a replacement technology for state-of-the-art spray, flash, and fluidized bed drying systems. Such systems are utilized in the food and kindred products; rubber products; chemical and allied products; stone, clay, and glass; textiles; and pulp and paper industrial sectors.

  8. Steam atmosphere drying concepts using steam exhaust recompression

    Energy Technology Data Exchange (ETDEWEB)

    DiBella, F.A. [TECOGEN, Inc., Waltham, MA (United States)

    1992-08-01

    In the US industrial drying accounts for approximately 1.5 quads of energy use per year. Annual industrial dryer expenditures are estimated to be in the $500 million range. Industrial drying is a significant energy and monetary expense. For the thermal drying processes in which water is removed via evaporation from the feedstock, attempts have been made to reduce the consumption of energy using exhaust waste heat recovery techniques, improved dryer designs, or even the deployment of advanced mechanical dewatering techniques. Despite these efforts, it is obvious that a large amount of thermal energy is often still lost if the latent heat of evaporation from the evaporated water cannot be recovered and/or in some way be utilized as direct heat input into the dryer. Tecogen Inc. is conducting research and development on an industrial drying concept. That utilizes a directly or indirectly superheated steam cycle atmosphere with exhaust steam recompression to recover the latent heat in the exhaust that would otherwise be lost. This approach has the potential to save 55 percent of the energy required by a conventional air dryer. Other advantages to the industrial dryer user include: A 35-percent reduction in the yearly cost per kg{sub evap} to dry wet feedstock, Reduced airborne emissions, Reduced dry dust fire/explosion risks, Hot product not exposed to oxygen thus, the product quality is enhanced, Constant rate drying in steam atmosphere, Reduced dryer size and cost, Reduced dryer heat losses due to lower dryer inlet temperatures. Tecogen has projected that the steam atmosphere drying system is most suitable as a replacement technology for state-of-the-art spray, flash, and fluidized bed drying systems. Such systems are utilized in the food and kindred products; rubber products; chemical and allied products; stone, clay, and glass; textiles; and pulp and paper industrial sectors.

  9. Unsteady coupling effects of wet steam in steam turbines flows

    International Nuclear Information System (INIS)

    Blondel, Frederic

    2014-01-01

    In addition to conventional turbomachinery problems, both the behavior and performances of steam turbines are highly dependent on the vapour thermodynamic state and the presence of a liquid phase. EDF, the main French electricity producer, is interested in further developing its' modelling capabilities and expertise in this area to allow for operational studies and long-term planning. This PhD thesis explores the modelling of wetness formation and growth in a steam turbine and an analysis of the coupling between the liquid phase and the main flow unsteadiness. To this end, the work in this thesis took the following approach. Wetness was accounted for using a homogeneous model coupled with transport equations to take into account the effects of non-equilibrium phenomena, such as the growth of the liquid phase and nucleation. The real gas attributes of the problem demanded adapted numerical methods. Before their implementation in the 3D elsA solver, the accuracy of the chosen models was tested using a developed one-dimensional nozzle code. In this manner, various condensation models were considered, including both poly-dispersed and monodispersed behaviours of the steam. Finally, unsteady coupling effects were observed from several perspectives (1D, 1D - 3D, 3D), demonstrating the ability of the method of moments to sustain unsteady phenomena which were not apparent in a simple monodispersed model. (author)

  10. Development of axial tomography technique for the study of steam explosion

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Young; Seo, S. W.; You, S. [Handong Golbal Univ., Pohang (Korea, Republic of)

    2006-05-15

    In this report, axial tomography applying to steam explosion is implemented. When steam explosion experiment is performed, we have seen the difficulty with physical modeling due to the complex phenomena of generated steam, propagation of shock wave and bubble breakup and coalescence. Hence, the uncertainty due to these phenomena is occurred. The fast and global measurement of the steam distribution is imperative to understand the complex phenomena performed during the steam explosion, KAERI have developed the fast and global measuring instrument to monitor such phenomena of axial steam distribution. Generally, X-ray is used as measuring method, but this method is very expensive and has limited measurement area. So we need new method that can substitute X-ray method and in this research, ECT method is replaced. The research is performed dividing within two parts: Software and Hardware. In the software part, the electric field analysis code and algorithm for inverse projection were developed. And, in the hardware part, capacitance measurement circuit is developed to measure up to fF level. Operable axial tomography was analyzed with concept design of axial tomography appropriate to steam explosion accident and analysis code for axial electric field analysis and inverse algorithm were developed, moreover, designing signal analysis system for axial tomography was performed.

  11. Changing the simualtor's steam generator

    International Nuclear Information System (INIS)

    Ruiz Martin, J.A.; Ortega Pascual, F.

    2006-01-01

    Two Spanish nuclear power plants (two PWR units each one) have planned to change their Westinghouse D-3 steam generators (SGo henceforth) for a new model, 61W/D3 from Siemens/KWU (SGn henceforth), during 1995/1997. This is the reason why TECNATOM has developed during 1994's last term, a new software for the full scope simulator that incorporates the modifications related to the steam generator substiution programme. This allows an anticipated training on the procedures, not only for normal, but for emergency procedures. As it is a component which has not yet been included in these plants, there are not real references or operative experience data. Therefore, the design of the validation strategy was one of the key points in this work. (author)

  12. Steam coal mines of tomorrow

    Energy Technology Data Exchange (ETDEWEB)

    McCloskey, G

    1986-07-01

    A comprehensive review of new steam coal mines being planned or developed worldwide. It shows that at least 20 major mines with a combined annual output of 110 million tonnes per annum, could add their coal to world markets in the next 10 years. The review highlights: substantial activity in Australia with at least four major mines at advanced planning stages; a strengthening of the South American export industry with 4 major mines operating in 10 years compared with just one today; no major export mines being developed in the traditional US mining areas; and the emergence of Indonesia as a major steam coal producer/exporter. The review also shows a reduction in cost/output ratios, and also the proximity of the new mines to existing infrastructure (e.g. export terminals, rail links).

  13. Organic evaporator steam valve failure

    International Nuclear Information System (INIS)

    Jacobs, R.A.

    1992-01-01

    Defense Waste Processing Facility (DWPF) Technical has requested an analysis of the capacity of the Organic Evaporator (OE) condenser (OEC) be performed to determine its capability in the case where the OE steam flow control valve fails open. Calculations of the OE boilup and the OEC heat transfer coefficient indicate the OEC will have more than enough capacity to remove the heat at maximum OE boilup. In fact, the Salt Cell Vent Condenser (SCVC) should also have sufficient capacity to handle the maximum OE boilup. Therefore, it would require simultaneous loss of OEC and/or SCVC condensing capacity for the steam valve failure to cause high benzene in the Process Vessel Vent System (PVVS)

  14. Closed loop steam cooled airfoil

    Science.gov (United States)

    Widrig, Scott M.; Rudolph, Ronald J.; Wagner, Gregg P.

    2006-04-18

    An airfoil, a method of manufacturing an airfoil, and a system for cooling an airfoil is provided. The cooling system can be used with an airfoil located in the first stages of a combustion turbine within a combined cycle power generation plant and involves flowing closed loop steam through a pin array set within an airfoil. The airfoil can comprise a cavity having a cooling chamber bounded by an interior wall and an exterior wall so that steam can enter the cavity, pass through the pin array, and then return to the cavity to thereby cool the airfoil. The method of manufacturing an airfoil can include a type of lost wax investment casting process in which a pin array is cast into an airfoil to form a cooling chamber.

  15. Steam generator waterlancing at DNGS

    International Nuclear Information System (INIS)

    Seppala, D.; Malaugh, J.

    1995-01-01

    Darlington Nuclear Generating Station (DNGS) is a four 900 MW Unit nuclear station forming part of the Ontario Hydro East System. There are four identical steam generators(SGs) per reactor unit. The Darlington SGs are vertical heat exchangers with an inverted U-tube bundle in a cylindrical shell. The DNGS Nuclear Plant Life Assurance Group , a department of DNGS Engineering Services have taken a Proactive Approach to ensure long term SG integrity. Instead of waiting until the tubesheets are covered by a substantial and established hard deposit; DNGS plan to clean each steam generator's tubesheet, first half lattice tube support assembly and bottom of the thermal plate every four years. The ten year business plan provides for cleaning and inspection to be conducted on all four SGs in each unit during maintenance outages (currently scheduled for every four years)

  16. Evaluation of steam for Meloidogyne Arenaria control in production of in-ground floriculture crops in Florida

    Science.gov (United States)

    Steam and soil solarization were investigated for control of the root-knot nematode Meloidogyne arenaria in two years of field trials on a commercial flower farm in Florida. The objective was to determine if pre-plant steam treatments in combination with solarization, or solarization alone effective...

  17. Corrosion of PWR steam generators

    International Nuclear Information System (INIS)

    Garnsey, R.

    1979-01-01

    Some designs of pressurized water reactor (PWR) steam generators have experienced a variety of corrosion problems which include stress corrosion cracking, tube thinning, pitting, fatigue, erosion-corrosion and support plate corrosion resulting in 'denting'. Large international research programmes have been mounted to investigate the phenomena. The operational experience is reviewed and mechanisms which have been proposed to explain the corrosion damage are presented. The implications for design development and for boiler and feedwater control are discussed. (author)

  18. Design features of Advanced Power Reactor (APR) 1400 steam generator

    International Nuclear Information System (INIS)

    Park, Tae-Jung; Park, Jun-Soo; Kim, Moo-Yong

    2004-01-01

    Advanced Power Reactor 1400 (APR 1400) which is to achieve the improvement of the safety and economical efficiency has been developed by Korea Hydro and Nuclear Power Co., Ltd. (KHNP) with the support from industries and research institutes. The steam generator for APR 1400 is an evolutionary type from System 80 + , which is the recirculating U-tube heat exchanger with integral economizer. Compared to the System 80 + steam generator, it is focused on the improved design features, operating and design conditions of APR 1400 steam generator. Especially, from the operation experience of Korean Standard Nuclear Power Plant (KSNP) steam generator, the lessons-learned measures are incorporated to prevent the tube wear caused by flow-induced vibration (FIV). The concepts for the preventive design features against FIV are categorized to two fields; flow distribution and dynamic response characteristics. From the standpoint of flow distribution characteristics, the egg-crate flow distribution plate (EFDP) is installed to prevent the local excessive flow loaded on the most susceptible tube to wear. The parametric study is performed to select the optimum design with the efficient mitigation of local excessive flow. ATHOS3 Mod-01 is used and partly modified to analyze the flow field of the APR 1400 steam generator. In addition, the upper tube bundle support is designed to eliminate the presence of tube with a low natural frequency. Based on the improved upper tube bundle support, the modal analysis is performed and compared with that of System 80 + . Using the results of flow distribution and modal analysis, the two mechanisms of flow-induced vibration are investigated; fluid-elastic instability (FEI) and random turbulence excitation (RTE). (authors)

  19. Study of scratch-induced stress corrosion cracking for steam generator tubes and scratch control

    International Nuclear Information System (INIS)

    Meng, F.; Xu, X.; Liu, X.; Wang, J.

    2014-01-01

    This paper introduces field cases for scratch-induced stress corrosion cracking (SISCC) of steam generator tubes in PWR and current studies in laboratories. According to analysis result of broke tubes, scratches caused intergranular stress corrosion cracking (IGSCC) with outburst. The effect of microstructure for nickel-base alloys, residual stresses caused by scratching process and water chemistry on SISCC and possible mechanism of SISCC are discussed. The result shows that scratch-induced microstructure evolution contributes to SISCC significantly. The causes of scratches during steam generator tubing manufacturing and installation process are stated and improved reliability with scratch control is highlighted for steam generator tubes in newly built nuclear power plants. (author)

  20. Study of scratch-induced stress corrosion cracking for steam generator tubes and scratch control

    Energy Technology Data Exchange (ETDEWEB)

    Meng, F.; Xu, X.; Liu, X. [Shanghai Nuclear Engineering Research and Design Institute, Shanghai (China); Wang, J. [Chinese Academy of Sciences, Institute of Metal Research, Shenyang (China)

    2014-07-01

    This paper introduces field cases for scratch-induced stress corrosion cracking (SISCC) of steam generator tubes in PWR and current studies in laboratories. According to analysis result of broke tubes, scratches caused intergranular stress corrosion cracking (IGSCC) with outburst. The effect of microstructure for nickel-base alloys, residual stresses caused by scratching process and water chemistry on SISCC and possible mechanism of SISCC are discussed. The result shows that scratch-induced microstructure evolution contributes to SISCC significantly. The causes of scratches during steam generator tubing manufacturing and installation process are stated and improved reliability with scratch control is highlighted for steam generator tubes in newly built nuclear power plants. (author)

  1. Large nuclear steam turbine plants

    International Nuclear Information System (INIS)

    Urushidani, Haruo; Moriya, Shin-ichi; Tsuji, Kunio; Fujita, Isao; Ebata, Sakae; Nagai, Yoji.

    1986-01-01

    The technical development of the large capacity steam turbines for ABWR plants was partially completed, and that in progress is expected to be completed soon. In this report, the outline of those new technologies is described. As the technologies for increasing the capacity and heightening the efficiency, 52 in long blades and moisture separating heaters are explained. Besides, in the large bore butterfly valves developed for making the layout compact, the effect of thermal efficiency rise due to the reduction of pressure loss can be expected. As the new technology on the system side, the simplification of the turbine system and the effect of heightening the thermal efficiency by high pressure and low pressure drain pumping-up method based on the recent improvement of feed water quality are discussed. As for nuclear steam turbines, the actual records of performance of 1100 MW class, the largest output at present, have been obtained, and as a next large capacity machine, the development of a steam turbine of 1300 MWe class for an ABWR plant is in progress. It can be expected that by the introduction of those new technologies, the plants having high economical efficiency are realized. (Kako, I.)

  2. Optimal design of marine steam turbine

    International Nuclear Information System (INIS)

    Liu Chengyang; Yan Changqi; Wang Jianjun

    2012-01-01

    The marine steam turbine is one of the key equipment in marine power plant, and it tends to using high power steam turbine, which makes the steam turbine to be heavier and larger, it causes difficulties to the design and arrangement of the steam turbine, and the marine maneuverability is seriously influenced. Therefore, it is necessary to apply optimization techniques to the design of the steam turbine in order to achieve the minimum weight or volume by means of finding the optimum combination of design parameters. The math model of the marine steam turbine design calculation was established. The sensitivities of condenser pressure, power ratio of HP turbine with LP turbine, and the ratio of diameter with height at the end stage of LP turbine, which influence the weight of the marine steam turbine, were analyzed. The optimal design of the marine steam turbine, aiming at the weight minimization while satisfying the structure and performance constraints, was carried out with the hybrid particle swarm optimization algorithm. The results show that, steam turbine weight is reduced by 3.13% with the optimization scheme. Finally, the optimization results were analyzed, and the steam turbine optimization design direction was indicated. (authors)

  3. Radiological protection for the ANGRA 1 steam generator replacement outage

    International Nuclear Information System (INIS)

    Oliveira, Magno Jose de; Amaral, Marcos Antonio do; Minelli, Edson; Ferreira, William Alves

    2009-01-01

    The Angra 1 Nuclear Power Plant (NPP) is a Westinghouse two-loop plant with net output before its 1P16 Outage of 632 MWe, with the Old Steam Generators (OSG) type model D3, which were replaced by two new Steam Generators with feed water-ring system. Localized in Angra dos Reis, Rio de Janeiro - Brazil, Angra 1 started in commercial operation in 1985 and, from the beginning problems related to corrosion have appeared in the Inconel 600 alloy of the tubes. The corrosion problems indicated the necessity for a strong control of the tubes thicknesses and, after a time, the ELETRONUCLEAR decided to replace the OSG. In 2009, ELETRONUCLEAR initiated in January 24, the actions for the Steam Generators Replacement - SGR. During the SGR process, several controls were applied in field, which made possible to have no radiological accidents, no dose limits exceeded, and permitted to achieve a very good result in terms of Collective Dose. This paper describes the radiological controls applied for the Angra 1 Steam Generator Replacement Outage, the radiological protection team sizing and distribution and the obtained results. (author)

  4. Leak suppression at steam generator man-, hand-, and eyeholes

    International Nuclear Information System (INIS)

    Sylvain, C.; Sutz, P.; Gemma, A.

    1988-01-01

    Plant unavailability associated with primary and secondary holes is approximately the same as that caused by steam generator tube defects, i.e., 0.5%. Problems encountered with steam generator man-, hand-, and eyeholes during plant operation have led Electricite de France (EdF) and Framatome to improve hole seal design and to develop robots for closing and cleaning them. The data base available in France in this field on some 150 steam generators in 900- and 1300-MW(electric) pressurized water reactors (the equivalent of 300 reactor-yr of operation) has been the base of the developments described in this paper. Incidents occurring in operation primarily concern had-and inspection holes located on the steam generator's secondary side. They include four kinds: (1) leakage detected in operation, requiring forced outages, (2) leakage detected during plant restart after a scheduled shutdown and resulting in a restart delay, (3) pitting of seal mating surfaces, not inducing any leakage but jeopardizing subsequent compliance and requiring difficult and costly repairs, and (4) seizing of screws or bolts. New primary and secondary hole stud tightening and maintenance machines help to improve the efficiency of the in-service closing operations. They provide savings of up to 80% on labor, duration of operations, and exposure

  5. Recent technology for nuclear steam turbine-generator units

    International Nuclear Information System (INIS)

    Moriya, Shin-ichi; Kuwashima, Hidesumi; Ueno, Takeshi; Ooi, Masao

    1988-01-01

    As the next nuclear power plants subsequent to the present 1,100 MWe plants, the technical development of ABWRs was completed, and the plan for constructing the actual plants is advanced. As for the steam turbine and generator facilities of 1,350 MWe output applied to these plants, the TC6F-52 type steam turbines using 52 in long blades, moisture separation heaters, butterfly type intermediate valves, feed heater drain pumping-up system and other new technologies for increasing the capacity and improving the thermal efficiency were adopted. In this paper, the outline of the main technologies of those and the state of examination when those are applied to the actual plants are described. As to the technical fields of the steam turbine system for ABWRs, the improvement of the total technologies of the plants was promoted, aiming at the good economical efficiency, reliability and thermal efficiency of the whole facilities, not only the main turbines. The basic specification of the steam turbine facilities for 50 Hz ABWR plants and the main new technologies applied to the turbines are shown. The development of 52 in long last stage blades, the development of the analysis program for the coupled vibration of the large rotor system, the development of moisture separation heaters, the turbine control system, condensate and feed water system, and the generators are described. (Kako, I.)

  6. Use of pulsed-neutron capture logs to identify steam breakthrough

    International Nuclear Information System (INIS)

    Masse, P.J.; Gosney, T.C.; Long, D.L.

    1991-01-01

    This paper reports on identification of steam-breakthrough zones in a stacked sand/shale sequence with variable lateral continuity which is difficult. Such identification, however, would allow the modification of field operations to enhance recovery through improved vertical sweep and heat injection. Twenty pulsed-neutron capture (PNC) logs were run to identify the steam-breakthrough zone(s) in a seven-pattern area of Mobil's Middle expansion (MIDX) Steamflood Project in the South Belridge field. These PNC data were combined with data from recent replacement wells and a detailed geologic analysis. Evaluation of this combined information allowed identification of potential steam-breakthrough zone(s), and operations were modified to reduce and eliminate steam breakthrough

  7. Potential application of radiogenic isotopes and geophysical methods to understand the hydrothermal dystem of the Upper Geyser Basin, Yellowstone National Park

    Science.gov (United States)

    Paces, James B.; Long, Andrew J.; Koth, Karl R.

    2015-01-01

    Numerous geochemical and geophysical studies have been conducted at Yellowstone National Park to better understand the hydrogeologic processes supporting the thermal features of the Park. This report provides the first 87Sr/86Sr and 234U/238U data for thermal water from the Upper Geyser Basin (UGB) intended to evaluate whether heavy radiogenic isotopes might provide insight to sources of groundwater supply and how they interact over time and space. In addition, this report summarizes previous geophysical studies made at Yellowstone National Park and provides suggestions for applying non-invasive ground and airborne studies to better understand groundwater flow in the subsurface of the UGB. Multiple samples from Old Faithful, Aurum, Grand, Oblong, and Daisy geysers characterized previously for major-ion concentrations and isotopes of water (δ2H, δ18O, and 3H) were analyzed for Sr and U isotopes. Concentrations of dissolved Sr and U are low (4.3–128 ng g-1 Sr and 0.026–0.0008 ng g-1 U); consequently only 87Sr/86Sr data are reported for most samples. Values of 87Sr/86Sr for most geysers remained uniform between April and September 2007, but show large increases in all five geysers between late October 2007 and early April, 2008. By late summer of 2008, 87Sr/86Sr values returned to values similar to those observed a year earlier. Similar patterns are not present in major-ion data measured on the same samples. Furthermore, large geochemical differences documented between geysers are not observed in 87Sr/86Sr data, although smaller differences between sites may be present. Sr-isotope data are consistent with a stratified hydrologic system where water erupted in spring and summer of 2007 and summer of 2008 equilibrated with local intracaldera rhyolite flows at shallower depths. Water erupted between October 2007 and April 2008 includes greater amounts of groundwater that circulated deep enough to acquire a radiogenic 87Sr/86Sr, most likely from Archean basement

  8. Steam generator group project progress report. Task 3, health physics

    International Nuclear Information System (INIS)

    Reece, W.D.; Hoenes, G.R.; Parkhurst, M.A.

    1984-01-01

    The gamma radiation fields in and around the retired Surry steam generator were measured extensively with thermoluminescent dosimeters (TLD's) and other standard radiation instruments. The techniques of measurement and the results are described for locations outside the shell, inside the channel head, and inside the secondary side of the steam generator. The gamma fields ranged from more than 10 R/hr in the middle of the tube bundle on the secondary side to less than 5 mR/hr at the bottom of the outside of the shell below the channel head. Co-60 was the only detected gamma emitter. The results of the measurements were used in an analytical model which predicted the Co-60 inventory to be between 70 and 87 curies

  9. Production-log base model for carbonate permeability distribution and steam flood optimization

    Energy Technology Data Exchange (ETDEWEB)

    Ahamed, S.F.; Choudhry, M.A.; Abdulbaqi, J.B. [Kuwait Gulf Oil Co. (Kuwait)

    2008-10-15

    This paper presented a model for the effective management of primary and thermal oil recovery operations in the Wafra Field in Kuwait, where a small huff and puff project was carried out in 1998 to determine if steam injection was a feasible recovery option for the field. The Eocene heavy oil reservoirs of the Wafra Field are carbonate rock admixtures with gypsum and anhydrite. They are the shallowest of the field's productive horizons and exhibit a high degree of fluid flow heterogeneity. The assessment of vertical and lateral permeability variation is a key factor for success of the reservoir development plan. Steam injection began in 2006 in a small scale test (SST) to determine if the innovative technology could produce steam from effluent water and to test the viability of steam injection in carbonate reservoirs. Following the success of the SST, a large scale pilot (LSP) is schedule to start in 2009. It can be used for completion strategies of injectors and producers in steam injection. The model showed that the productivity of the Eocene wells could be correlated with common available logs to develop a log based-permeability model. A series of cross plots for the perforated intervals of high and low productivity wells were constructed to develop a relationship between well productivity and location of log parameters on the plots. A relationship between rock quality, productivity and conventional log parameters was established. It was concluded that the vertical permeability and interwell continuity in the Eocene wells can be used to optimize new well placement for horizontal and vertical infill drilling. The model is also an effective tool to predict the steam injectivity profile to understand the anomalies related to temperature-depth distribution. The model can be used to improve the efficiency of formation heating by optimizing the steam flood process and steam pattern well completion. 16 refs.

  10. PROFIL-360 high resolution steam generator tube profilometry system

    International Nuclear Information System (INIS)

    Glass, S.W.

    1985-01-01

    A high-resolution profilometry system, PROFIL 360, has been developed to assess the condition of steam generator tubes and rapidly produce the data to evaluate the potential for developing in-service leaks. The probe has an electromechanical sensor in a rotating head. This technique has been demonstrated in the field, saving tubes that would have been plugged with the go-gauge criterion and indicating plugging other high-risk candidates that might otherwise not have been removed from service

  11. Profil-360 high resolution steam generator tube profilometry system

    International Nuclear Information System (INIS)

    Glass, S.W.

    1985-01-01

    A high-resolution profilometry system, PROFIL 360, has been developed to assess the condition of steam generator tubes and rapidly produce the data to evaluate the potential for developing in-service leaks. The probe has an electromechanical sensor in a rotating head. This technique has been demonstrated in the field, saving tubes that would have been plugged with the go-gauge criterion and indicating plugging other high-risk candidates that might otherwise not have been removed from service

  12. The development of control systems for high power steam turbines

    International Nuclear Information System (INIS)

    Mathey, M.

    1983-01-01

    The functional and technological aspects of developments in the field of control systems for steam turbines over the last twenty years are analyzed. These developments have now culminated in very sophisticated systems which closely link electronics to high pressure hydraulic technology. A detailed description of these systeme high-lighting the high technical level of the control methods and the flexibility and reliability in service of turbines controlled in this way is given [fr

  13. Performance demonstration requirements for eddy current steam generator tube inspection

    International Nuclear Information System (INIS)

    Kurtz, R.J.; Heasler, P.G.; Anderson, C.M.

    1992-10-01

    This paper describes the methodology used for developing performance demonstration tests for steam generator tube eddy current (ET) inspection systems. The methodology is based on statistical design principles. Implementation of a performance demonstration test based on these design principles will help to ensure that field inspection systems have a high probability of detecting and correctly sizing tube degradation. The technical basis for the ET system performance thresholds is presented. Probability of detection and flaw sizing tests are described

  14. Review on steam generator tube failure propagation study in Japan

    International Nuclear Information System (INIS)

    Tanabe, Hiromi; Wachi, Eiji

    1990-01-01

    Major objectives of a failure propagation study in Japan are to understand the leak development behavior, to develop an analytical method based on the knowledge obtained through the experiments, and finally to apply it to actual LMFBR steam generators to evaluate the conservatism of design basis leak (DBL) of the plants. Therefore, various kinds of experimental study in relevant fields were conducted using SWAT test facilities and the LEAP code was developed. (author). 2 figs

  15. Isolation and characterization of a CO2-tolerant Lactobacillus strain from Crystal Geyser, Utah, U.S.A.

    Science.gov (United States)

    Santillan, Eugenio Felipe; Shanahan, Timothy; Omelon, Christopher; Major, Jonathan; Bennett, Philip

    2015-07-01

    When CO2 is sequestered into the deep subsurface, changes to the subsurface microbial community will occur. Capnophiles, microorganisms that grow in CO2-rich environments, are some organisms that may be selected for under the new environmental conditions. To determine whether capnophiles comprise an important part of CO2-rich environments, an isolate from Crystal Geyser, Utah, U.S.A., a CO2- rich spring considered a carbon sequestration analogue, was characterized. The isolate was cultured under varying CO2, pH, salinity, and temperature, as well as different carbon substrates and terminal electron acceptors (TEAs) to elucidate growth conditions and metabolic activity. Designated CG-1, the isolate is related (99%) to Lactobacillus casei in 16S rRNA gene identity, growing at PCO2 between 0 to 1.0 MPa. Growth is inhibited at 2.5 MPa, but stationary phase cultures exposed to this pressure survive beyond 5 days. At 5.0 MPa, survival is at least 24 hours. CG-1 grows in neutral pH, 0.25 M NaCl, and between 25° to 45°C andconsumes glucose, lactose, sucrose, or crude oil, likely performing lactic acid fermentation. Fatty acid profiles between 0.1 MPa to 1.0 MPa suggests decreases in cell size and increases in membrane rigidity. Transmission electron microscopy reveals rod shaped bacteria at 0.1 MPa. At 1.0 MPa, cells are smaller, amorphous, and produce abundant capsular material. Its ability to grow in environments regardless of the presence of CO2 suggests we have isolated an organism that is more capnotolerant than capnophilic. Results also show that microorganisms are capable of surviving the stressful conditions created by the introduction of CO2 for sequestration. Furthermore, our ability to culture an environmental isolate indicates that organisms found in CO2 environments from previous genomic and metagenomics studies are viable, metabolizing, and potentially affecting the surrounding environment.

  16. Isolation and characterization of a CO2-tolerant Lactobacillus strain from Crystal Geyser, Utah, U.S.A.

    Directory of Open Access Journals (Sweden)

    Eugenio Felipe U Santillan

    2015-07-01

    Full Text Available When CO2 is sequestered into the deep subsurface, changes to the subsurface microbial community will occur. Capnophiles, microorganisms that grow in CO2-rich environments, are some organisms that may be selected for under the new environmental conditions. To determine whether capnophiles comprise an important part of CO2-rich environments, an isolate from Crystal Geyser, Utah, U.S.A., a CO2- rich spring considered a carbon sequestration analogue, was characterized. The isolate was cultured under varying CO2, pH, salinity, and temperature, as well as different carbon substrates and terminal electron acceptors (TEAs to elucidate growth conditions and metabolic activity. Designated CG-1, the isolate is related (99% to Lactobacillus casei in 16S rRNA gene identity, growing at PCO2 between 0 to 1.0 MPa. Growth is inhibited at 2.5 MPa, but stationary phase cultures exposed to this pressure survive beyond 5 days. At 5.0 MPa, survival is at least 24 hours. CG-1 grows in neutral pH, 0.25 M NaCl, and between 25° to 45°C andconsumes glucose, lactose, sucrose, or crude oil, likely performing lactic acid fermentation. Fatty acid profiles between 0.1 MPa to 1.0 MPa suggests decreases in cell size and increases in membrane rigidity. Transmission electron microscopy reveals rod shaped bacteria at 0.1 MPa. At 1.0 MPa, cells are smaller, amorphous, and produce abundant capsular material. Its ability to grow in environments regardless of the presence of CO2 suggests we have isolated an organism that is more capnotolerant than capnophilic. Results also show that microorganisms are capable of surviving the stressful conditions created by the introduction of CO2 for sequestration. Furthermore, our ability to culture an environmental isolate indicates that organisms found in CO2 environments from previous genomic and metagenomics studies are viable, metabolizing, and potentially affecting the surrounding environment.

  17. Thermal-hydraulics in recirculating steam generators

    International Nuclear Information System (INIS)

    Carver, M.B.; Carlucci, L.N.; Inch, W.W.R.

    1981-04-01

    This manual describes the THIRST code and its use in computing three-dimensional two-phase flow and heat transfer in a steam generator under steady state operation. The manual is intended primarily to facilitate the application of the code to the analysis of steam generators typical of CANDU nuclear stations. Application to other steam generator designs is also discussed. Details of the assumptions used to formulate the model and to implement the numerical solution are also included

  18. Exergy Steam Drying and Energy Integration

    Energy Technology Data Exchange (ETDEWEB)

    Verma, Prem; Muenter, Claes (Exergy Engineering and Consulting, SE-417 55 Goeteborg (Sweden)). e-mail: verma@exergyse.com

    2008-10-15

    Exergy Steam Drying technology has existed for past 28 years and many new applications have been developed during this period. But during past few years the real benefits have been exploited in connection with bio-fuel production and energy integration. The steam dryer consists of a closed loop system, where the product is conveyed by superheated and pressurised carrier steam. The carrier steam is generated by the water vapours from the product being dried, and is indirectly superheated by another higher temperature energy source such as steam, flue gas, thermal oil etc. Besides the superior heat transfer advantages of using pressurised steam as a drying medium, the energy recovery is efficient and simple as the recovered energy (80-90%) is available in the form of steam. In some applications the product quality is significantly improved. Examples presented in this paper: Bio-Combine for pellets production: Through integration of the Exergy Steam Dryer for wood with a combined heat and power (CHP) plant, together with HP steam turbine, the excess carrier steam can be utilised for district heating and/or electrical power production in a condensing turbine. Bio-ethanol production: Both for first and second generation of ethanol can the Exergy process be integrated for treatment of raw material and by-products. Exergy Steam Dryer can dry the distillers dark grains and solubles (DDGS), wood, bagasse and lignin. Bio-diesel production: Oil containing seeds and fruits can be treated in order to improve both the quality of oil and animal feed protein, thus minimizing further oil processing costs and increasing the sales revenues. Sewage sludge as bio-mass: Municipal sewage sludge can be considered as a renewable bio-fuel. By drying and incineration, the combustion heat value of the sludge is sufficient for the drying process, generation of electrical energy and production of district heat. Keywords; Exergy, bio-fuel, bio-mass, pellets, bio-ethanol, biodiesel, bio

  19. Analysis of performance for centrifugal steam compressor

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Seung Hwan; Ryu, Chang Kook; Ko, Han Seo [Sungkyunkwan University, Suwon (Korea, Republic of)

    2016-12-15

    In this study, mean streamline and Computational fluid dynamics (CFD) analyses were performed to investigate the performance of a small centrifugal steam compressor using a latent heat recovery technology. The results from both analysis methods showed good agreement. The compression ratio and efficiency of steam were found to be related with those of air by comparing the compression performances of both gases. Thus, the compression performance of steam could be predicted by the compression performance of air using the developed dimensionless parameters.

  20. Analysis of performance for centrifugal steam compressor

    International Nuclear Information System (INIS)

    Kang, Seung Hwan; Ryu, Chang Kook; Ko, Han Seo

    2016-01-01

    In this study, mean streamline and Computational fluid dynamics (CFD) analyses were performed to investigate the performance of a small centrifugal steam compressor using a latent heat recovery technology. The results from both analysis methods showed good agreement. The compression ratio and efficiency of steam were found to be related with those of air by comparing the compression performances of both gases. Thus, the compression performance of steam could be predicted by the compression performance of air using the developed dimensionless parameters

  1. Steam plant for pressurized water reactors

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    This book discusses the research and development organisations and users to highlight those aspects of the steam turbine and associated plant which are particularly related to the PWR system. The contents include: Characteristics of the steam system (including feed train, dump system and safety aspects); overall design aspects of high and half speed turbines; design aspects of the steam generator and seismic considerations; moisture separators and reheaters; feed pumps and their drives; water treatment; safety related valves; operational experience; availability and performance

  2. Steam Turbine Flow Path Seals (a Review)

    Science.gov (United States)

    Neuimin, V. M.

    2018-03-01

    Various types of shroud, diaphragm, and end seals preventing idle leak of working steam are installed in the flow paths of steam turbine cylinders for improving their efficiency. Widely known labyrinth seals are most extensively used in the Russian turbine construction industry. The category of labyrinth seals also includes seals with honeycomb inserts. The developers of seals with honeycomb inserts state that the use of such seals makes it possible to achieve certain gain due to smaller leaks of working fluid and more reliable operation of the system under the conditions in which the rotor rotating parts may rub against the stator elements. However, a positive effect can only be achieved if the optimal design parameters of the honeycomb structure are fulfilled with due regard to the specific features of its manufacturing technology and provided that this structure is applied in a goal-seeking manner in the seals of steam and gas turbines and compressors without degrading their vibration stability. Calculated and preliminary assessments made by experts testify that the replacement of conventional labyrinth seals by seals with honeycomb inserts alone, due to which the radial gaps in the shroud seal can be decreased from 1.5 to 0.5 mm, allows the turbine cylinder efficiency to be increased at the initial stage by approximately 1% with the corresponding gain in the turbine set power output. The use of rectangular-cellular seals may result, according to estimates made by their developers, in a further improvement of turbine efficiency by 0.5-1.0%. The labor input required to fabricate such seals is six to eight times smaller than that to fabricate labyrinth seals with honeycomb inserts. Recent years have seen the turbine construction companies of the United States and Germany advertising the use of abradable (sealing) coatings (borrowed from the gas turbine construction technology) in the turbine designs instead of labyrinth seals. The most efficient performance of

  3. Loss of feed flow, steam generator tube rupture and steam line break thermohydraulic experiments

    Energy Technology Data Exchange (ETDEWEB)

    Mendler, O J; Takeuchi, K; Young, M Y

    1986-10-01

    The Westinghouse Model Boiler No. 2 (MB-2) steam generator test model at the Engineering Test Facility in Tampa, Florida, was reinstrumented and modified for performing a series of tests simulating steam generator accident transients. The transients simulated were: loss of feed flow, steam generator tube rupture, and steam line break events. This document presents a description of (1) the model boiler and the associated test facility, (2) the tests performed, and (3) the analyses of the test results.

  4. Loss of feed flow, steam generator tube rupture and steam line break thermohydraulic experiments

    International Nuclear Information System (INIS)

    Mendler, O.J.; Takeuchi, K.; Young, M.Y.

    1986-10-01

    The Westinghouse Model Boiler No. 2 (MB-2) steam generator test model at the Engineering Test Facility in Tampa, Florida, was reinstrumented and modified for performing a series of tests simulating steam generator accident transients. The transients simulated were: loss of feed flow, steam generator tube rupture, and steam line break events. This document presents a description of (1) the model boiler and the associated test facility, (2) the tests performed, and (3) the analyses of the test results

  5. CAREM-25 Steam Generator Stability Analysis

    International Nuclear Information System (INIS)

    Rabiti, A.; Delmastro, D.

    2003-01-01

    In this work the stability of a once-through CAREM-25 steam generator is analyzed.A fix nodes numerical model, that allows the modelling of the liquid, two-phase and superheated steam zones, is implemented.This model was checked against a mobile finite elements model under saturated steam conditions at the channel exit and a good agreement was obtained.Finally the stability of a CAREM steam generator is studied and the range of in let restrictions that a assure the system stability is analyzed

  6. Amazing & extraordinary facts the steam age

    CERN Document Server

    Holland, Julian

    2012-01-01

    Respected transport author Julian Holland delves into the intriguing world of steam in his latest book, which is full of absorbing facts and figures on subjects ranging from Cornish beam engines, steam railway locomotives, road vehicles and ships through to traction engines, steam rollers and electricity generating stations and the people who designed and built them. Helped along the way by the inventive minds of James Watt, Richard Trevithick and George Stephenson, steam became the powerhouse that drove the Industrial Revolution in Britain in the late 18th and 19th centuries.

  7. Method to detect steam generator tube leakage

    International Nuclear Information System (INIS)

    Watabe, Kiyomi

    1994-01-01

    It is important for plant operation to detect minor leakages from the steam generator tube at an early stage, thus, leakage detection has been performed using a condenser air ejector gas monitor and a steam generator blow down monitor, etc. In this study highly-sensitive main steam line monitors have been developed in order to identify leakages in the steam generator more quickly and accurately. The performance of the monitors was verified and the demonstration test at the actual plant was conducted for their intended application to the plants. (author)

  8. Flow structure of steam-water mixed spray

    International Nuclear Information System (INIS)

    Sanada, Toshiyuki; Mitsuhashi, Yuki; Mizutani, Hiroya; Saito, Takayuki

    2010-01-01

    In this study, the flow structure of a steam-water mixed spray is studied both numerically and experimentally. The velocity and pressure profiles of single-phase flow are calculated using numerical methods. On the basis of the calculated flow fields, the droplet behavior is predicted by a one-way interaction model. This numerical analysis reveals that the droplets are accelerated even after they are sprayed from the nozzle. Experimentally, the mixed spray is observed using an ultra-high-speed video camera, and the velocity field is measured by using the oarticle image velocimetry (PIV) technique. Along with this PIV velocity field measurement, the velocities and diameters of droplets are measured by phase Doppler anemometry. Furthermore, the mixing process of steam and water and the atomization process of a liquid film are observed using a transparent nozzle. High-speed photography observations reveal that the flow inside the nozzle is annular flow and that most of the liquid film is atomized at the nozzle throat and nozzle outlet. Finally, the optimum mixing method for steam and water is determined.

  9. Flow structure of steam-water mixed spray

    Energy Technology Data Exchange (ETDEWEB)

    Sanada, Toshiyuki, E-mail: ttsanad@ipc.shizuoka.ac.j [Department of Mechanical Engineering, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8561, Shizuoka (Japan); Mitsuhashi, Yuki; Mizutani, Hiroya; Saito, Takayuki [Department of Mechanical Engineering, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8561, Shizuoka (Japan)

    2010-12-15

    In this study, the flow structure of a steam-water mixed spray is studied both numerically and experimentally. The velocity and pressure profiles of single-phase flow are calculated using numerical methods. On the basis of the calculated flow fields, the droplet behavior is predicted by a one-way interaction model. This numerical analysis reveals that the droplets are accelerated even after they are sprayed from the nozzle. Experimentally, the mixed spray is observed using an ultra-high-speed video camera, and the velocity field is measured by using the oarticle image velocimetry (PIV) technique. Along with this PIV velocity field measurement, the velocities and diameters of droplets are measured by phase Doppler anemometry. Furthermore, the mixing process of steam and water and the atomization process of a liquid film are observed using a transparent nozzle. High-speed photography observations reveal that the flow inside the nozzle is annular flow and that most of the liquid film is atomized at the nozzle throat and nozzle outlet. Finally, the optimum mixing method for steam and water is determined.

  10. Load histories from steam explosions during core melt accidents

    International Nuclear Information System (INIS)

    Jacobs, H.; Kolev, N.I.

    1992-01-01

    For the analysis of steam explosions a multicomponent multiphase thermohydraulic code is required which describes at least the motions of melt, water, and steam by separate velocity fields. One example of these very rare codes is the IVA3 code the development of which was brought to an interim close in 1991. As an example of a typical application of this code, precalculations of the FARO LWR Scoping Test 2 performed at Ispra are discussed. Unfortunately, the calculation results cannot be compared directly to the test results because of important differences between planned and achieved test parameters. Above all, only about one third of the planned melt mass actually entered the water. The test was performed in a closed vessel at an initial pressure of 50 bar. The water was saturated at this temperature and its level was at 1 m height. The simulation starts with the release of 50 kg of simulated corium from an intermediate catcher at about 3.2 m height. The calculation predicts a gradual pressure rise without fast transients worth mentioning from 50 to about 76 bar within roughly one second and stabilizes slightly below the maximum. Also described are the material distributions predicted during the process and the 'mixed' masses according to two different criteria. The former indicate that the melt jet penetrates the water without desintegrating while being surrounded by a thick vapor layer. Subsequently the melt collects at the level bottom and much of the liquid water is blown upwards by the steam being produced. The amounts of mass being 'mixed' with liquid water (and thus are thought to potentially participate in a steam explosion) remain below 10% for the known Theofanous criterion and below 30% for a more conservative criterion. It is however more important that the calculation demonstrates that further mixing could be the result of the onset of a steam explosion. This may strongly limit the usefulness of local mixing criteria. (orig./DG)

  11. Steam microturbines in distributed cogeneration

    CERN Document Server

    Kicinski, Jan

    2014-01-01

    This book presents the most recent trends and concepts in power engineering, especially with regard to prosumer and civic energy generation. In so doing, it draws widely on his experience gained during the development of steam microturbines for use in small combined heat and power stations based on the organic Rankine cycle (CHP-ORC). Major issues concerning the dynamic properties of mechanical systems, in particular rotating systems, are discussed, and the results obtained when using unconventional bearing systems, presented. Modeling and analysis of radial-flow and axial-flow microturbines a

  12. Lifetime of superheated steam components

    International Nuclear Information System (INIS)

    Stoklossa, K.H.; Oude-Hengel, H.H.; Kraechter, H.J.

    1974-01-01

    The current evaluation schemes in use for judging the lifetime expectations of superheated steam components are compared with each other. The influence of pressure and temperature fluctuations, the differences in the strength of the wall, and the spread band of constant-strainrates are critically investigated. The distribution of these contributory effects are demonstrated in the hight of numerous measuring results. As an important supplement to these evaluation schemes a newly developed technique is introduced which is designed to calculate failure probabilities. (orig./RW) [de

  13. Strategic management of steam generators

    International Nuclear Information System (INIS)

    Hernalsteen, P.; Berthe, J.

    1991-01-01

    This paper addresses the general approach followed in Belgium for managing any kind of generic defect affecting a Steam Generator tubebundle. This involves the successive steps of: problem detection, dedicated sample monitoring, implementation of preventive methods, development of specific plugging criteria, dedicated 100% inspection, implementation of repair methods, adjusted sample monitoring and repair versus replacement strategy. These steps are illustrated by the particular case of Primary Water Stress Corrosion Cracking in tube roll transitions, which is presently the main problem for two Belgian units Doele-3 and Tihange-2. (author)

  14. Steam generator for nuclear reactors

    International Nuclear Information System (INIS)

    Byerley, W.M.; Bennett, R.R.

    1978-01-01

    In the steam generator, the primary medium is led through a U-shaped tube bundle heating up a secondary medium (feedwater) which flows around the tube bundle via a preheating chamber. In order to optimize heat transfer inside the preheating chamber, the feedwater is separated into a counterflow and a parallel flow with regard to the primary medium by means of partitioning walls and deflectors. The ratio is 70/30%. This way, boiling in the preheater is avoided, i.e. the high LMTD (logaritmic mean temperature difference) is fully utilized. (DG) [de

  15. Thermal performances of molten salt steam generator

    International Nuclear Information System (INIS)

    Yuan, Yibo; He, Canming; Lu, Jianfeng; Ding, Jing

    2016-01-01

    Highlights: • Thermal performances of molten salt steam generator were experimentally studied. • Overall heat transfer coefficient reached maximum with optimal molten salt flow rate. • Energy efficiency first rose and then decreased with salt flow rate and temperature. • Optimal molten salt flow rate and temperature existed for good thermal performance. • High inlet water temperature benefited steam generating rate and energy efficiency. - Abstract: Molten salt steam generator is the key technology for thermal energy conversion from high temperature molten salt to steam, and it is used in solar thermal power station and molten salt reactor. A shell and tube type molten salt steam generator was set up, and its thermal performance and heat transfer mechanism were studied. As a coupling heat transfer process, molten salt steam generation is mainly affected by molten salt convective heat transfer and boiling heat transfer, while its energy efficiency is also affected by the heat loss. As molten salt temperature increased, the energy efficiency first rose with the increase of heat flow absorbed by water/steam, and then slightly decreased for large heat loss as the absorbed heat flow still rising. At very high molten salt temperature, the absorbed heat flow decreased as boiling heat transfer coefficient dropping, and then the energy efficiency quickly dropped. As the inlet water temperature increased, the boiling region in the steam generator remarkably expanded, and then the steam generation rate and energy efficiency both rose with the overall heat transfer coefficient increasing. As the molten salt flow rate increased, the wall temperature rose and the boiling heat transfer coefficient first increased and then decreased according to the boiling curve, so the overall heat transfer coefficient first increased and then decreased, and then the steam generation rate and energy efficiency of steam generator both had maxima.

  16. The testing of a steam-water separating device used for vertical steam generators

    International Nuclear Information System (INIS)

    Ding Xunshen; Cui Baoyuan; Xue Yunkui; Liu Shixun

    1989-01-01

    The air-water screening tests of a steam-water separating device used for vertical steam generators at low pressure are introduced. The article puts emphasis on the qualification test of the steam-water separating device at hot conditions in a high temperature and pressure water test rig. The performance of the comprehensive test of the steam-water separating device indicates that the humidity of the steam at the drier exit is much less than the specified amount of 0.25%

  17. Procedure for generating steam and steam generator for operating said procedure

    International Nuclear Information System (INIS)

    Chlique, Bernard.

    1975-01-01

    This invention concerns the generation of steam by bringing the water to be vaporised into indirect thermal exchange relation with the heating steam which condenses when passing in series, along alternate routes, through bundles of tubes immersed in a vaporising chamber. A number of steam generators working on this principle already exist. The purpose of the invention is to modify the operating method of these steam generators by means of a special disposition making it possible to build a compact unit including an additional bundle of tubes heated by the condensates collected at the outlet of each bundle through which the heating steam passes [fr

  18. Formaldehyde as a carbon and electron shuttle between autotroph and heterotroph populations in acidic hydrothermal vents of Norris Geyser Basin, Yellowstone National Park

    Energy Technology Data Exchange (ETDEWEB)

    Moran, James J.; Whitmore, Laura M.; Isern, Nancy G.; Romine, Margaret F.; Riha, Krystin M.; Inskeep, William P.; Kreuzer, Helen W.

    2016-03-19

    The Norris Geyser Basin in Yellowstone National Park contains a large number of hydrothermal systems, which host microbial populations supported by primary productivity associated with a suite of chemolithotrophic metabolisms. We demonstrate that Metallosphaera yellowstonesis MK1, a facultative autotrophic archaeon isolated from a hyperthermal acidic hydrous ferric oxide (HFO) spring in Norris Geyser Basin, excretes formaldehyde during autotrophic growth. To determine the fate of formaldehyde in this low organic carbon environment, we incubated native microbial mat (containing M. yellowstonensis) from a HFO spring with 13C-formaldehyde. Isotopic analysis of incubation-derived CO2 and biomass showed that formaldehyde was both oxidized and assimilated by members of the community. Autotrophy, formaldehyde oxidation, and formaldehyde assimilation displayed different sensitivities to chemical inhibitors, suggesting that distinct sub-populations in the mat selectively perform these functions. Our results demonstrate that electrons originally resulting from iron oxidation can energetically fuel autotrophic carbon fixation and associated formaldehyde excretion, and that formaldehyde is both oxidized and assimilated by different organisms within the native microbial community. Thus, formaldehyde can effectively act as a carbon and electron shuttle connecting the autotrophic, iron oxidizing members with associated heterotrophic members in the HFO community.

  19. Control device for steam turbine

    International Nuclear Information System (INIS)

    Hoshi, Hiroyuki.

    1993-01-01

    A power load imbalance detection circuit detects a power load imbalance when a load variation coefficient is large and output-load deviation is great. Then, it self-holds and causes a timer to start counting up and releases the self-holding after the elapse of a certain period of time. Upon load separation caused by system accidents, the power load imbalance detection circuit operates along with the increase of turbine rpm, to operate the control valve abrupt closing circuit and a bypassing value abrupt opening circuit. Then, self-holding of the power load imbalance detection circuit is released and, subsequently, a steam control value and a bypass valve are controlled by a control valve flow rate demand signal and a bypass flow rate demand signal determined by an entire main steam flow rate signal and a speed/load control signal. Accordingly, the turbine rpm is settled to about a rated rpm. This enables to avoid reactor shutdown upon occurrence of load interruption. (I.N.)

  20. Steam generation process control and automation; Automacao e controle no processo de geracao de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Souza Junior, Jose Cleodon de; Silva, Walmy Andre C.M. da [PETROBRAS S.A., Natal, RN (Brazil)

    2004-07-01

    This paper describes the implementation of the Supervisory Control and Data Acquisition System (SCADA) in the steam generation process for injection in heavy oil fields of the Alto do Rodrigues Production Asset, developed by PETROBRAS/E and P/UN-RNCE. This Asset is located in the northeastern region of Brazil, in Rio Grande do Norte State. It addresses to the steam generators for injection in oil wells and the upgrade project that installed remote terminal units and a new panel controlled by PLC, changed all the pneumatic transmitters by electronic and incorporated the steam quality and oxygen control, providing the remote supervision of the process. It also discusses the improvements obtained in the steam generation after the changes in the conception of the control and safety systems. (author)

  1. Third international seminar on horizontal steam generators

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    The Third International Seminar on Horizontal Steam Generators held on October 18-20, 1994 in Lappeenranta, consisted of six sessions dealing with the topics: thermal hydraulic experiments and analyses, primary collector integrity, management of primary-to-secondary leakage accidents, feedwater collector replacement and discussion of VVER-440 steam generator safety issues.

  2. Third international seminar on horizontal steam generators

    International Nuclear Information System (INIS)

    1995-01-01

    The Third International Seminar on Horizontal Steam Generators held on October 18-20, 1994 in Lappeenranta, consisted of six sessions dealing with the topics: thermal hydraulic experiments and analyses, primary collector integrity, management of primary-to-secondary leakage accidents, feedwater collector replacement and discussion of VVER-440 steam generator safety issues

  3. Containments for consolidated nuclear steam systems

    International Nuclear Information System (INIS)

    Jabsen, F.S.

    1978-01-01

    A containment system for a consolidated nuclear steam system incorporating a nuclear core, steam generator and reactor coolant pumps within a single pressure vessel is described which is designed to provide radiation shielding and pressure suppression. Design details, including those for the dry well and wet well of the containment, are given. (UK)

  4. Steam injection : analysis of a typical application.

    NARCIS (Netherlands)

    Penning, F.M.; Lange, de H.C.

    1996-01-01

    A cardboard factory requires steam and electricity, which are produced in its own powerplant. Conventional cogeneration systems cannot cope with the large fluctuations in steam demand, inherent to the cardboard production process, while power demand remains almost constant. For this reason, two

  5. Sintering of nickel steam reforming catalysts

    DEFF Research Database (Denmark)

    Sehested, Jens; Larsen, Niels Wessel; Falsig, Hanne

    2014-01-01

    . In this paper, particle migration and coalescence in nickel steam reforming catalysts is studied. Density functional theory calculations indicate that Ni-OH dominate nickel transport at nickel surfaces in the presence of steam and hydrogen as Ni-OH has the lowest combined energies of formation and diffusion...

  6. Third international seminar on horizontal steam generators

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    The Third International Seminar on Horizontal Steam Generators held on October 18-20, 1994 in Lappeenranta, consisted of six sessions dealing with the topics: thermal hydraulic experiments and analyses, primary collector integrity, management of primary-to-secondary leakage accidents, feedwater collector replacement and discussion of VVER-440 steam generator safety issues.

  7. Steam generator leak detection using acoustic method

    International Nuclear Information System (INIS)

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

    1982-05-01

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

  8. Steam Reformer With Fibrous Catalytic Combustor

    Science.gov (United States)

    Voecks, Gerald E.

    1987-01-01

    Proposed steam-reforming reactor derives heat from internal combustion on fibrous catalyst. Supplies of fuel and air to combustor controlled to meet demand for heat for steam-reforming reaction. Enables use of less expensive reactor-tube material by limiting temperature to value safe for material yet not so low as to reduce reactor efficiency.

  9. Steam-frothing of milk for coffee

    DEFF Research Database (Denmark)

    Münchow, Morten; Jørgensen, Leif; Amigo Rubio, Jose Manuel

    2015-01-01

    A method for evaluation of the foaming properties of steam-frothed milk, based on image analysis (feature extraction) carried out on a video taken immediately after foam formation, was developed. The method was shown to be able to analyse steam-frothed milk made using a conventional espresso mach...

  10. LMR steam generator blowdown with RETRAN

    International Nuclear Information System (INIS)

    Wei, T.Y.C.

    1985-01-01

    One of the transients being considered in the FSAR Chapter 15 analyses of anticipated LMR transients is the fast blowdown of a steam generator upon inadvertent actuation of the liquid metal/water reaction mitigation system. For the blowdown analysis, a stand-alone steam generator model for the IFR plant was constructed using RETRAN

  11. Water regime of steam power plants

    International Nuclear Information System (INIS)

    Oesz, Janos

    2011-01-01

    The water regime of water-steam thermal power plants (secondary side of pressurized water reactors (PWR); fossil-fired thermal power plants - referred to as steam power plants) has changed in the past 30 years, due to a shift from water chemistry to water regime approach. The article summarizes measures (that have been realised by chemists of NPP Paks) on which the secondary side of NPP Paks has become a high purity water-steam power plant and by which the water chemistry stress corrosion risk of heat transfer tubes in the VVER-440 steam generators was minimized. The measures can also be applied to the water regime of fossil-fired thermal power plants with super- and subcritical steam pressure. Based on the reliability analogue of PWR steam generators, water regime can be defined as the harmony of construction, material(s) and water chemistry, which needs to be provided in not only the steam generators (boiler) but in each heat exchanger of steam power plant: - Construction determines the processes of flow, heat and mass transfer and their local inequalities; - Material(s) determines the minimal rate of general corrosion and the sensitivity for local corrosion damage; - Water chemistry influences the general corrosion of material(s) and the corrosion products transport, as well as the formation of local corrosion environment. (orig.)

  12. Signal analysis of steam line acoustics

    International Nuclear Information System (INIS)

    Martin, C. Samuel

    2003-01-01

    The vibration of nuclear steam piping is usually associated with pressure fluctuations emanating from flow disturbances such as steam generator nozzles, bends, or other pipe fittings. Flow separation at pipe tees and within steam chest manifolds or headers generate pressure fluctuations that propagate both upstream to steam generators as well as downstream to the steam turbine. Steady-state acoustic oscillations at various frequencies occur within the piping, possibly exciting structural vibrations. This paper focuses on the assessment of the origin of the disturbances using signal analyses of two dynamic pressure recordings from pressure transducers located along straight runs in the steam piping. The technique involves performing the cross spectrum to two dynamic pressure signals in piping between (1) the steam generator and steam chest header, and (2) between the header and steam turbine outlet. If, at a specified frequency, no causality occurs between the two signals then the cross spectra magnitude will be negligible. Of interest here is the value of the phase between the two signals for frequencies for which the magnitude of the cross spectrum is not negligible. It is shown in the paper that the direction of the dominant waves at all frequencies can be related to the phase angle from the cross spectrum. It has to be realized that pressure waves emanating from one source such as a steam generator will propagate along uniform steam pipes with little transformation or attenuation, but will be reflected at fittings and at inlets and outlets. Hence, the eventual steady-state time record at a given location in the piping is a result of not only the disturbance, but also reflections of earlier pulsations. Cross-spectral analyses has been employed to determine the direction of the dominant acoustic waves in the piping for various frequencies for which there are signals. To prove the technique, synthetic spectra are generated comprised of harmonic waves moving both

  13. Acoustic tool for leak inspections in steam generator divider plates

    International Nuclear Information System (INIS)

    Kowalewski, J.; Maak, P.; Colbert, M.

    1997-01-01

    Cross flow leakage through divider plates in the primary head of steam generators, may be a contributor to RIHT rise which can have a negative effect on the operation of a plant. A method to provide quick and reliable inspection of divider plate leakage can be very useful in helping make timely and effective maintenance decisions. A novel acoustic tool for performing inspections in drained steam generators during shutdowns has been developed by OH Technologies and successfully demonstrated in a field application. The technique, referred as ALIS (acoustic leak inspection system), performs a scan of the divider plate face and presents a graphic image of the leakage paths and an estimate of the total leakage area. (author)

  14. Steam gasification of coal, project prototype plant nuclear process heat

    International Nuclear Information System (INIS)

    Heek, K.H. van

    1982-05-01

    This report describes the tasks, which Bergbau-Forschung has carried out in the field of steam gasification of coal in cooperation with partners and contractors during the reference phase of the project. On the basis of the status achieved to date it can be stated, that the mode of operation of the gas-generator developed including the direct feeding of caking high volatile coal is technically feasible. Moreover through-put can be improved by 65% at minimum by using catalysts. On the whole industrial application of steam gasification - WKV - using nuclear process heat stays attractive compared with other gasification processes. Not only coal is conserved but also the costs of the gas manufactured are favourable. As confirmed by recent economic calculations these are 20 to 25% lower. (orig.) [de

  15. Ultrasonic downcomer flow measurements for recirculating steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Janzen, Victor, E-mail: Victor.Janzen@cnl.ca [Canadian Nuclear Laboratories, Chalk River, ON, Canada K0 J 1J0 (Canada); Luloff, Brian [Canadian Nuclear Laboratories, Chalk River, ON, Canada K0 J 1J0 (Canada); Sedman, Ken [Nuclear Safety Analysis & Support Department, Bruce Power, Toronto, ON, Canada M5G 1X6 (Canada)

    2015-08-15

    Highlights: • Measuring recirculating flow in nuclear steam generators provides useful information. • Flow measurements shed light on component performance and degradation mechanisms. • Commonly used ultrasonic technology and application methods are described. • Results of measurements at several power reactors are summarized. • Potential improvements in reliability and flexibility of application are suggested. - Abstract: Measurements of downcomer flow in nuclear steam generators can provide unique fitness for service and performance indicators related to overall thermalhydraulic performance, safety related secondary-side setpoints and certain forms of degradation. This paper reviews the benefits of downcomer-flow measurements to nuclear power–plant operators, and describes methods that are commonly used. It summarizes the history and state-of-the-art of the most widely used technology, non-intrusive ultrasonic systems, including field applications at several nuclear power plants. It also describes the technical challenges that remain, and summarizes recent technical developments and future improvements.

  16. Operating experiences with 1 MW steam generator

    Energy Technology Data Exchange (ETDEWEB)

    Sano, A; Kanamori, A; Tsuchiya, T

    1975-07-01

    1 MW steam generator, which was planned as the first stage of steam generator development in Power Reactor and Nuclear Fuel Corp. (PNC) in Japan, is a single-unit, once-through, integrated shell and tube type with multi-helical coil tubes. It was completed in Oarai Engineering Center of PNC in March of 1971, and the various performance tests were carried out up to April, 1972. After the dismantle of the steam generator for structural inspection and material test, it was restored with some improvements. In this second 1 MW steam generator, small leak occurred twice during normal operation. After repairing the failure, the same kind of performance tests as the first steam generator were conducted in order to verify the thermal insulation effect of argon gas in downcomer zone from March to June, 1974. In this paper the above operating experiences were presented including the outline of some performance test results. (author)

  17. Strategic maintenance plan for Cernavoda steam generators

    International Nuclear Information System (INIS)

    Cicerone, T.; Dhar, D.; VandenBerg, J.P.

    2002-01-01

    Steam generators are among the most important pieces of equipment in a nuclear power plant. They are required full time during the plant operation and obviously no redundancy exists. Past experience has shown that those utilities which implemented comprehensive steam generator inspection and maintenance programs and strict water chemistry controls, have had good steam generator performance that supports good overall plant performance. The purpose of this paper is to discuss a strategic Life Management and Operational-monitoring program for the Cernavoda steam generators. The program is first of all to develop a base of expertise for the management of the steam generator condition; and that is to be supported by a program of actions to be accomplished over time to assess their condition, to take measures to avoid degradation and to provide for inspections, cleaning and modifications as necessary. (author)

  18. Circumferential cracking of steam generator tubes

    International Nuclear Information System (INIS)

    Karwoski, K.J.

    1997-04-01

    On April 28, 1995, the U.S. Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 95-03, open-quote Circumferential Cracking of Steam Generator Tubes.close-quote GL 95-03 was issued to obtain information needed to verify licensee compliance with existing regulatory requirements regarding the integrity of steam generator tubes in domestic pressurized-water reactors (PWRs). This report briefly describes the design and function of domestic steam generators and summarizes the staff's assessment of the responses to GL 95-03. The report concludes with several observations related to steam generator operating experience. This report is intended to be representative of significant operating experience pertaining to circumferential cracking of steam generator tubes from April 1995 through December 1996. Operating experience prior to April 1995 is discussed throughout the report, as necessary, for completeness

  19. Maintenance and repair of LMFBR steam generators

    International Nuclear Information System (INIS)

    Verriere, P.; Alanche, J.; Minguet, J.L.

    1984-06-01

    After some general remarks on the French fast neutron system, this paper presents the state of the program for the construction of fast reactor in France. Then, the general design of Super Phenix 1 steam generator components is outlined and, the in-service monitoring systems and protective devices with which they are equiped are briefly described. The methods used, in the event of leakage, for leak location, steam generator inspection, steam generator repair and putting the affected loop back into service, are discussed. There are two main lines of research, relating respectively to the means of water leak detection in sodium and the inspection arrangements that will be used either periodically, or following a sodium-water reaction. Finally, after a brief description of the steam generator, this paper describes the four incidents (leaks) that occurred on the Phenix steam generator in the course of 1982 and 1983, and the subsequent repair operations

  20. A drier unit for steam separators

    International Nuclear Information System (INIS)

    Peyrelongue, J.-P.

    1973-01-01

    Description is given of a drier unit adapted to equip a water separator mounted in a unit for treating a wet steam fed from a high pressure enclosure, so as to dry and contingently superheat said steam prior to injecting same into a turbine low pressure stage. This drier unit is constituted by at least a stack of separating sheets maintained in parallel relationship and at a slight angle with respect to the horizontal so as to allow the water provided by wet steam to flow toward a channel communicating with a manifold, and by means for guiding the steam between the sheets and evenly distributing it. This can be applied to steam turbines in nuclear power stations [fr

  1. Testing installation for a steam generator

    International Nuclear Information System (INIS)

    Dubourg, M.

    1985-01-01

    The invention proposes a testing installation for a steam generator associated to a boiler, comprising a testing exchanger connected to a feeding circuit in secondary fluid and to a circuit to release the steam produced, and comprising a heating-tube bundle connected to a closed circuit of circulation of a primary coolant at the same temperature and at the pressure than the primary fluid. The heating-tube bundle of the testing exchanger has the same height than the primary bundle of the steam generator and the testing exchanger is at the same level and near the steam generator and is fed by the same secondary fluid such as it is subject to the same operation phases during a long period. The in - vention applies, more particularly, to the steam generators of pressurized water nuclear power plants [fr

  2. Characteristics of steam jet impingement on annulus

    International Nuclear Information System (INIS)

    Yoon, Sang H.; Kim, Won J.; Suh, Kune Y.; Song, Chul H.

    2004-01-01

    The steam jet impingement occurs when the steam through the cold leg from the steam generator strikes the inner reactor barrel during the reflood phase of a loss-of-coolant accident (LOCA), which is a characteristic behavior for the APR1400 (Advanced Power Reactor 1400 MWe). In the cold leg break LOCA, the steam and water flows in the downcomer are truly multidimensional. The azimuthal velocity distribution of the steam flow has an important bearing on the thermal hydraulic phenomena such as the emergency coolant water direct bypass, sweepout, steam condensation, and so forth. The investigation of jet flow is required to determine the steam path and momentum reduction rate after the impingement. For the observation of the steam behavior near the break, the computational fluid dynamic (CFD) analysis has been carried out using CFX5.6. The flow visualization and analysis demonstrate the velocity profiles of the steam flow in the annulus region for the same boundary conditions. Pursuant to the CFD results, the micro-Pitot tubes were positioned at varying angles, and corrected for their sensitivity. The experiments were carried out to directly measure the pressure differential and to visualize the flow utilizing a smoke injection method. Results from this study are slated to be applied to MARS, which is a thermal hydraulic system code for the best-estimate analysis. The current one- or two-dimensional analysis in MARS was known to distort the local flow behavior. To enhance prediction capability of MARS, it is necessary to inspect the steam path in the break flow and mechanically simulate the momentum variation. The present experimental and analytical results can locally be applied to developing the engineering models of specific and essential phenomena. (author)

  3. Crump Geyser Exploration and Drilling Project. High Precision Geophysics and Detailed Structural Exploration and Slim Well Drilling

    Energy Technology Data Exchange (ETDEWEB)

    Fairbank, Brian D. [Nevada Geothermal Power Company, Vancouver (Canada); Smith, Nicole [Nevada Geothermal Power Company, Vancouver (Canada)

    2015-06-10

    The Crump Geyser Exploration and Drilling Project – High Precision Geophysics and Detailed Structural Exploration and Slim Well Drilling ran from January 29, 2010 to September 30, 2013. During Phase 1 of the project, collection of all geophysical surveys was completed as outlined in the Statement of Project Objectives. In addition, a 5000-foot full sized exploration well was drilled by Ormat, and preexisting drilling data was discovered for multiple temperature gradient wells within the project area. Three dimensional modeling and interpretation of results from the geophysical surveys and drilling data gave confidence to move to the project into Phase 2 drilling. Geological and geophysical survey interpretations combined with existing downhole temperature data provided an ideal target for the first slim-hole drilled as the first task in Phase 2. Slim-hole 35-34 was drilled in September 2011 and tested temperature, lithology, and permeability along the primary range-bounding fault zone near its intersection with buried northwest-trending faults that have been identified using geophysical methods. Following analysis of the results of the first slim-hole 35-34, the second slim hole was not drilled and subsequent project tasks, including flowing differential self-potential (FDSP) surveys that were designed to detail the affect of production and injection on water flow in the shallow aquifer, were not completed. NGP sold the Crump project to Ormat in August 2014, afterwards, there was insufficient time and interest from Ormat available to complete the project objectives. NGP was unable to continue managing the award for a project they did not own due to liability issues and Novation of the award was not a viable option due to federal award timelines. NGP submitted a request to mutually terminate the award on February 18, 2015. The results of all of the technical surveys and drilling are included in this report. Fault interpretations from surface geology, aeromag

  4. Isolation and characterization of a CO2-tolerant Lactobacillus strain from Crystal Geyser, Utah, U.S.A.

    Energy Technology Data Exchange (ETDEWEB)

    Santillan, Eugenio-Felipe U.; Shanahan, Timothy M.; Omelon, Christopher R.; Major, Jonathan R.; Bennett, Philip C.

    2015-07-23

    When CO2 is sequestered into the deep subsurface, changes to the subsurface microbial community will occur. Capnophiles, microorganisms that grow in CO2-rich environments, are some organisms that may be selected for under the new environmental conditions. To determine whether capnophiles comprise an important part of CO2-rich environments, an isolate from Crystal Geyser, Utah, U.S.A., a CO2- rich spring considered a carbon sequestration analog, was characterized. The isolate was cultured under varying CO2, pH, salinity, and temperature, as well as different carbon substrates and terminal electron acceptors (TEAs) to elucidate growth conditions and metabolic activity. Designated CG-1, the isolate is related (99%) to Lactobacillus casei in 16S rRNA gene identity, growing at PCO2 between 0 and 1.0 MPa. Growth is inhibited at 2.5 MPa, but stationary phase cultures exposed to this pressure survive beyond 5 days. At 5.0 MPa, survival is at least 24 h. CG-1 grows in neutral pH, 0.25 M NaCl, and between 25° and 45°C and consumes glucose, lactose, sucrose, or crude oil, likely performing lactic acid fermentation. Fatty acid profiles between 0.1 and 1.0 MPa suggests decreases in cell size and increases in membrane rigidity. Transmission electron microscopy reveals rod shaped bacteria at 0.1 MPa. At 1.0 MPa, cells are smaller, amorphous, and produce abundant capsular material. Its ability to grow in environments regardless of the presence of CO2 suggests we have isolated an organism that is more capnotolerant than capnophilic. Results also show that microorganisms are capable of surviving the stressful conditions created by the introduction of CO2 for sequestration. Furthermore, our ability to culture an environmental isolate indicates that organisms found in CO2 environments from previous genomic and metagenomics studies are viable, metabolizing, and potentially affecting the

  5. Steam sources in El Salvador and their economic importance

    Energy Technology Data Exchange (ETDEWEB)

    Grebe, W H [Geologisches Staatsinstitut Hamburg, DE

    1957-01-01

    A geographical survey is provided of important steam and hot water sources (temperature greater than 60/sup 0/C) in El Salvador. These sources are tabulated and are described in the text. They appear as fumaroles, solfatarae, mudpots, mud fields, and hot springs. A series of calorimetric measurements was made in 1955. For electrical power production, development will probably be restricted to those fields located within the young volcanic areas, as these areas correspond to those of greatest population density. As of 1957, the use of these resources was limited to the production of sulfur and kaolinite from a few small-scale boreholes.

  6. Analytical Model of Steam Chamber Evolution from Vertical Well

    Science.gov (United States)

    Shevchenko, D. V.; Usmanov, S. A.; Shangaraeva, A. I.; Murtaizin, T. A.

    2018-05-01

    This paper is aimed to check the possibility of applying the Steam Assisted Gravity Drainage in vertical wells. This challenge seems to be vital because most of the natural bitumen reservoirs are found to occur above the oil fields being developed so that a well system is already available at the stage of field management. The existing vertical wells are hard to be used for horizontal sidetracking in most of cases as the bitumen reservoir occurs at a shallow depth. The matter is to use the existing wells as vertical ones. At the same time, it is possible to drill an additional sidetrack as a producer or an injector.

  7. Model and control scheme for recirculation mode direct steam generation parabolic trough solar power plants

    International Nuclear Information System (INIS)

    Guo, Su; Liu, Deyou; Chen, Xingying; Chu, Yinghao; Xu, Chang; Liu, Qunming; Zhou, Ling

    2017-01-01

    Highlights: •A nonlinear dynamic model of recirculation DSG parabolic trough is developed. •Collector row, water separator and spray attemperator are modeled, respectively. •The dynamic behaviors of the collector field are simulated and analyzed. •Transfer functions of water level and outlet fluid temperature are derived. •Multi-model switching generalized predictive control strategy is developed. -- Abstract: This work describes and evaluates a new nonlinear dynamic model, and a new generalized predictive control scheme for a collector field of direct steam generation parabolic troughs in recirculation mode. Modeling the dynamic behaviors of collector fields is essential to design, testing and validation of automatic control systems for direct steam generation parabolic troughs. However, the behaviors of two-phase heat transfer fluids impose challenges to simulating and developing process control schemes. In this work, a new nonlinear dynamic model is proposed, based on the nonlinear distributed parameter and the nonlinear lumped parameter methods. The proposed model is used to simulate and analyze the dynamic behaviors of the entire collector field for recirculation mode direct steam generation parabolic troughs under different weather conditions, without excessive computational costs. Based on the proposed model, transfer functions for both the water level of the separator and outlet steam temperatures are derived, and a new multi-model switching generalized predictive control scheme is developed for simulated control of the plant behaviors for a wide region of operational conditions. The proposed control scheme achieves excellent control performance and robustness for systems with long delay, large inertia and time-varying parameters, and efficiently solves the model mismatching problem in direct steam generation parabolic troughs. The performances of the model and control scheme are validated with design data from the project of Integration of Direct

  8. Local two-phase modeling of the water-steam flows occurring in steam generators

    International Nuclear Information System (INIS)

    Denefle, Romain

    2013-01-01

    The present study is related to the need of modeling the two-phase flows occurring in a steam generator (liquid at inlet and vapour at outlet). The choice is made to investigate a hybrid modeling of the flow, considering the gas phase as two separated fields, each one being modeled with different closure laws. In so doing, the small and spherical bubbles are modeled through a dispersed approach within the two-fluid model, and the distorted bubbles are simulated with an interface locating method. The main outcome is about the implementation, the verification and the validation of the model dedicated to the large and distorted bubbles, as well as the coupling of the two approaches for the gas, allowing the presentation of demonstration calculations using the so-called hybrid approach. (author)

  9. fields

    Directory of Open Access Journals (Sweden)

    Brad J. Arnold

    2014-07-01

    Full Text Available Surface irrigation, such as flood or furrow, is the predominant form of irrigation in California for agronomic crops. Compared to other irrigation methods, however, it is inefficient in terms of water use; large quantities of water, instead of being used for crop production, are lost to excess deep percolation and tail runoff. In surface-irrigated fields, irrigators commonly cut off the inflow of water when the water advance reaches a familiar or convenient location downfield, but this experience-based strategy has not been very successful in reducing the tail runoff water. Our study compared conventional cutoff practices to a retroactively applied model-based cutoff method in four commercially producing alfalfa fields in Northern California, and evaluated the model using a simple sensor system for practical application in typical alfalfa fields. These field tests illustrated that the model can be used to reduce tail runoff in typical surface-irrigated fields, and using it with a wireless sensor system saves time and labor as well as water.

  10. Phenomenological modelling of steam explosions

    International Nuclear Information System (INIS)

    Corradini, M.L.; Drumheller, D.S.

    1980-01-01

    During a hypothetical core meltdown accident, an important safety issue to be addressed is the potential for steam explosions. This paper presents analysis and modelling of experimental results. There are four observations that can be drawn from the analysis: (1) vapor explosions are suppressed by noncondensible gases generated by fuel oxidation, by high ambient pressure, and by high water temperatures; (2) these effects appear to be trigger-related in that an explosion can again be induced in some cases by increasing the trigger magnitude; (3) direct fuel liquid-coolant liquid contact can explain small scale fuel fragmentation; (4) heat transfer during the expansion phase of the explosion can reduce the work potential

  11. Steam up over reactor policy

    International Nuclear Information System (INIS)

    Kovan, D.

    1976-01-01

    Britain is once more assessing its nuclear power programme in the light of recent forecasts that there is unlikely to be any growth in the demand for electricity for many years to come. This means that the extra costs of launching a commercially unproven reactor, the Steam Generating Heavy Water Reactor (SGHWR), will be an even greater burden than previously expected, because they would be spread over fewer reactors. Sir John Hill's reported assessment concludes that the present strategy would be the most expensive way of developing Britain's nuclear power programme; and under the circumstances, may not be the best option. The SGHWR programme will certainly be more expensive than either relaunching a programme of advanced gas-cooled reactors (AGRs), or building American designed pressurised water reactors (PWRs). Recent developments of the AGR and PWR's and their advantages in the present position are outlined. (U.K.)

  12. Endoscopic inspection of steam turbines

    International Nuclear Information System (INIS)

    Maliniemi, H.; Muukka, E.

    1990-01-01

    For over ten years, Imatran Voima Oy (IVO) has developed, complementary inspection methods for steam turbine condition monitoring, which can be applied both during operation and shutdown. One important method used periodically during outages is endoscopic inspection. The inspection is based on the method where the internal parts of the turbine is inspected through access borings with endoscope and where the magnified figures of the internal parts is seen on video screen. To improve inspection assurance, an image-processing based pattern recognition method for cracks has been developed for the endoscopic inspection of turbine blades. It is based on the deduction conditions derived from the crack shape. The computer gives an alarm of a crack detection and prints a simulated image of the crack, which is then checked manually

  13. Design of PFBR steam generator

    International Nuclear Information System (INIS)

    Chetal, S.C.; Bhoje, S.B.; Mitra, T.K.; Paranjpe, S.R.; Vaidyanathan, G.

    1990-01-01

    Vertical straight tube with an expansion bend in sodium path is the design selected for the steam generators of 500 MWe Prototype Fast Breeder Reactor (PFBR). There are 4 secondary loops with each loop consisting of 3 modules. With sodium reheat incorporated each module comprises of one evaporator, superheater and reheater. Material of construction is 2.25Cr-1Mo for evaporator and 9Cr-1Mo for superheater and reheater. The tube to tubesheet weld is internal bore butt weld with tubesheet having raised spigot. Aim is to have reliable design with higher plant availability. Design considerations leading to the choice of design features selected are discussed in the paper and a ''reference'' design has been described. (author). 2 figs, 1 tab

  14. The effect of steam separataor efficiency on transient following a steam line break

    International Nuclear Information System (INIS)

    Choi, J.H.; Ohn, M.Y.; Lee, N.H.; Hwang, S.T.; Lee, S.K.

    1996-01-01

    Detailed thermalhydraulic simulations for CANDU 6 steam line break inside containment are performed to predict the response of the primary and secondary circuits. The analysis is performed using the thermalhydraulic computer code, CATHENA, with a coupled primary and secondary circuit model. A two-loop representation of the primary and secondary circuits is modelled. The secondary circuit model includes the feedwater line from the deaerator storage tank, multi-node steam generators and the steam line up to the turbine. Two cases were carried out using different assumptions for the efficiency of the steam separators. Case 1 assumes the efficiency of the steam separators becomes zero when the water level in the steam drum increases to the elevation of primary cyclones, or the outlet flow from the steam generator becomes higher than 150 % of normal flow. Case 2 assumes the efficiency becomes zero only when the water level in the steam drum reaches the elevation of primary cyclones. The simulation results show that system responses are sensitive to the assumption for the efficiency of the steam separators and case 1 gives higher discharge energy. Fuel cooling is assured, since primary circuit is cooled down sufficiently by the steam generators for both cases. (author)

  15. Analysis of experimental characteristics of multistage steam-jet electors of steam turbines

    Science.gov (United States)

    Aronson, K. E.; Ryabchikov, A. Yu.; Brodov, Yu. M.; Brezgin, D. V.; Zhelonkin, N. V.; Murmanskii, I. B.

    2017-02-01

    A series of questions for specification of physical gas dynamics model in flow range of steam-jet unit and ejector computation methodology, as well as functioning peculiarities of intercoolers, was formulated based on analysis of experimental characteristics of multistage team-jet steam turbines. It was established that coefficient defining position of critical cross-section of injected flow depends on characteristics of the "sound tube" zone. Speed of injected flow within this tube may exceed that of sound, and pressure jumps in work-steam decrease at the same time. Characteristics of the "sound tube" define optimal axial sizes of the ejector. According to measurement results, the part of steam condensing in the first-stage coolant constitutes 70-80% of steam amount supplied into coolant and is almost independent of air content in steam. Coolant efficiency depends on steam pressure defined by operation of steam-jet unit of ejector of the next stage after coolant of steam-jet stage, temperature, and condensing water flow. As a rule, steam entering content of steam-air mixture supplied to coolant is overheated with respect to saturation temperature of steam in the mixture. This should be taken into account during coolant computation. Long-term operation causes changes in roughness of walls of the ejector's mixing chamber. The influence of change of wall roughness on ejector characteristic is similar to the influence of reverse pressure of the steam-jet stage. Until some roughness value, injection coefficient of the ejector stage operating in superlimiting regime hardly changed. After reaching critical roughness, the ejector switches to prelimiting operating regime.

  16. Future development of large steam turbines

    International Nuclear Information System (INIS)

    Chevance, A.

    1975-01-01

    An attempt is made to forecast the future of the large steam turbines till 1985. Three parameters affect the development of large turbines: 1) unit output; and a 2000 to 2500MW output may be scheduled; 2) steam quality: and two steam qualities may be considered: medium pressure saturated or slightly overheated steam (light water, heavy water); light enthalpie drop, high pressure steam, high temperature; high enthalpic drop; and 3) the quality of cooling supply. The largest range to be considered might be: open system cooling for sea-sites; humid tower cooling and dry tower cooling. Bi-fluid cooling cycles should be also mentioned. From the study of these influencing factors, it appears that the constructor, for an output of about 2500MW should have at his disposal the followings: two construction technologies for inlet parts and for high and intermediate pressure parts corresponding to both steam qualities; exhaust sections suitable for the different qualities of cooling supply. The two construction technologies with the two steam qualities already exist and involve no major developments. But, the exhaust section sets the question of rotational speed [fr

  17. Steam generating system in LMFBR type reactors

    International Nuclear Information System (INIS)

    Kurosawa, Katsutoshi.

    1984-01-01

    Purpose: To suppress the thermal shock loads to the structures of reactor system and secondary coolant system, for instance, upon plant trip accompanying turbine trip in the steam generation system of LMFBR type reactors. Constitution: Additional feedwater heater is disposed to the pipeway at the inlet of a steam generator in a steam generation system equipped with a closed loop extended from a steam generator by way of a gas-liquid separator, a turbine and a condensator to the steam generator. The separated water at high temperature and high pressure from a gas-liquid separator is heat exchanged with coolants flowing through the closed loop of the steam generation system in non-contact manner and, thereafter, introduced to a water reservoir tank. This can avoid the water to be fed at low temperature as it is to the steam generator, whereby the thermal shock loads to the structures of the reactor system and the secondary coolant system can be suppressed. (Moriyama, K.)

  18. International examples of steam generator replacement

    International Nuclear Information System (INIS)

    Wiechmann, K.

    1993-01-01

    Since 1979-1980 a total of twelve nuclear power plants world-wide have had their steam generators replaced. The replacement of the Combustion steam generators in the Millstone-2 plant in the United States was completed very recently. Steam generator replacement activities are going on at present in four plants. In North Anna, the steam generators have been under replacement since January 1990. In Japan, preparations have been started for Genkai-1. Since January 1992, the two projects in Beznau-1, Switzerland, and Doel-3, Belgium, have bee planned and executed in parallel. Why steam generator replacement? There are a number of defect mechanisms which give rise to the need for early steam generator replacement. One of the main reasons is the use of Inconel-600 as material for the heating tubes. Steam generator heating tubes made of Inconel-600 have been known to exhibit their first defects due to stress corrosion cracking after less than one year of operation. (orig.) [de

  19. An expert system for steam generator maintenance

    International Nuclear Information System (INIS)

    Remond, A.

    1988-01-01

    The tube bundles in PWR steam generators are, by far, the major source of problems whether they are due to primary and secondary side corrosion mechanisms or to tube vibration-induced wear at tube support locations. Because of differences in SG operating, materials, and fabrication processes, the damage may differ from steam generator to steam generator. MPGV, an expert system for steam generator maintenance uses all steam generator data containing data on materials, fabrication processes, inservice inspection, and water chemistry. It has access to operational data for individual steam generators and contains models of possible degradation mechanisms. The objectives of the system are: · Diagnosing the most probable degradation mechanism or mechanisms by reviewing the entire steam generator history. · Identifying the tubes most exposed to future damage and evaluating the urgency of repair by simulating the probable development of the problem in time. · Establishing the appropriate preventive actions such as repair, inspection or other measures and establishing an action schedule. The system is intended for utilities either for individual plants before each inspection outage or any time an incident occurs or for a set of plants through a central MPGV center. (author)

  20. Failure analysis of retired steam generator tubings

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hong Pyo; Kim, J. S.; Hwang, S. S. and others

    2005-04-15

    Degradation of steam generator leads to forced outage and extension of outage, which causes increase in repair cost, cost of purchasing replacement power and radiation exposure of workers. Steam generator tube rupture incident occurred in Uljin 4 in 2002, which made public sensitive to nuclear power plant. To keep nuclear energy as a main energy source, integrity of steam generator should be demonstrated. Quantitative relationship between ECT(eddy current test) signal and crack size is needed in assesment of integrity of steam generator in pressurized water reactor. However, it is not fully established for application in industry. Retired steam generator of Kori 1 has many kinds of crack such as circumferential and axial primary water stress corrosion crack and outer diameter stress corrosion crack(ODSCC). So, it can be used in qualifying and improving ECT technology and in condition monitoring assesment for crack detected in ISI(in service inspection). In addition, examination of pulled tube of Kori 1 retired steam generator will give information about effectiveness of non welded sleeving technology which was employed to repair defect tubes and remedial action which was applied to mitigate ODSCC. In this project, hardware such as semi hot lab. for pulled tube examination and modification transportation cask for pulled tube and software such as procedure of transportation of radioactive steam generator tube and non-destructive and destructive examination of pulled tube were established. Non-destructive and destructive examination of pulled tubes from Kori 1 retired steam generator were performed in semi hot lab. Remedial actions applied to Kori 1 retired steam generator, PWSCC trend and bulk water chemistry and crevice chemistry in Kori 1 were evaluated. Electrochemical decontamination technology for pulled tube was developed to reduce radiation exposure and enhance effectiveness of pulled tube examination. Multiparameter algorithm developed at ANL, USA was

  1. Dynamic modelling of nuclear steam generators

    International Nuclear Information System (INIS)

    Kerlin, T.W.; Katz, E.M.; Freels, J.; Thakkar, J.

    1980-01-01

    Moving boundary, nodal models with dynamic energy balances, dynamic mass balances, quasi-static momentum balances, and an equivalent single channel approach have been developed for steam generators used in nuclear power plants. The model for the U-tube recirculation type steam generator is described and comparisons are made of responses from models of different complexity; non-linear versus linear, high-order versus low order, detailed modeling of the control system versus a simple control assumption. The results of dynamic tests on nuclear power systems show that when this steam generator model is included in a system simulation there is good agreement with actual plant performance. (author)

  2. Selective hydrogenation processes in steam cracking

    Energy Technology Data Exchange (ETDEWEB)

    Bender, M.; Schroeter, M.K.; Hinrichs, M.; Makarczyk, P. [BASF SE, Ludwigshafen (Germany)

    2010-12-30

    Hydrogen is the key elixir used to trim the quality of olefinic and aromatic product slates from steam crackers. Being co-produced in excess amounts in the thermal cracking process a small part of the hydrogen is consumed in the ''cold part'' of a steam cracker to selectively hydrogenate unwanted, unsaturated hydrocarbons. The compositions of the various steam cracker product streams are adjusted by these processes to the outlet specifications. This presentation gives an overview over state-of-art selective hydrogenation technologies available from BASF for these processes. (Published in summary form only) (orig.)

  3. High speed drying of saturated steam

    International Nuclear Information System (INIS)

    Marty, C.; Peyrelongue, J.P.

    1993-01-01

    This paper describes the development of the drying process for the saturated steam used in the PWR nuclear plant turbines in order to prevent negative effects of water on turbine efficiency, maintenance costs and equipment lifetime. The high speed drying concept is based on rotating the incoming saturated steam in order to separate water which is more denser than the steam; the water film is then extracted through an annular slot. A multicellular modular equipment has been tested. Applications on high and low pressure extraction of various PWR plants are described (Bugey, Loviisa)

  4. Steam Generator Inspection Planning Expert System

    International Nuclear Information System (INIS)

    Rzasa, P.

    1987-01-01

    Applying Artificial Intelligence technology to steam generator non-destructive examination (NDE) can help identify high risk locations in steam generators and can aid in preparing technical specification compliant eddy current test (ECT) programs. A steam Generator Inspection Planning Expert System has been developed which can assist NDE or utility personnel in planning ECT programs. This system represents and processes its information using an object oriented declarative knowledge base, heuristic rules, and symbolic information processing, three artificial intelligence based techniques incorporated in the design. The output of the system is an automated generation of ECT programs. Used in an outage inspection, this system significantly reduced planning time

  5. IAEA Technical Meeting on Innovative Heat Exchanger and Steam Generator Designs for Fast Reactors. Working Material

    International Nuclear Information System (INIS)

    2011-01-01

    The IAEA, within the framework of its Nuclear Energy Department’s Technical Working Group on Fast Reactors (TWG-FR), assists Member States activities in fast reactors technology development areas by providing an umbrella for information exchange [topical Technical Meetings (TMs), Workshops and large Conferences] and collaborative R&D [Coordinated Research Projects (CRPs)]. The Technical meeting on “Innovative Heat Exchanger and Steam Generator Designs for Fast Reactors” was held from 21 – 22 December 2011 in Vienna, addressing Member States’ expressed needs of information exchange in the field of advanced fast reactor design features, with particular attention to innovative heat exchangers and steam generators. The Objective of the TM is to provide a global forum for in-depth information exchange and discussion on the most advanced concepts of heat exchangers and steam generators for fast reactors. More specifically, the objectives are: · Review of the status of advanced fast reactor development activities with special emphasis on design and performance of heat exchangers and steam generators; · Discuss requirements for innovative heat exchangers and steam generators; · Present results of studies and conceptual designs for innovative heat exchangers and steam generators; · Provide recommendations for international collaboration under the IAEA aegis. The meeting agenda of the meeting is in Annex I

  6. Scale Thickness Measurement of Steam Generator Tubing Using Eddy Current Signal of Bobbin Coil

    International Nuclear Information System (INIS)

    Kim, Chang Soo; Um, Ki Soo; Kim, Jae Dong

    2012-01-01

    Steam generator is one of the major components of nuclear power plant and steam generator tubes are the pressure boundary between primary and secondary side, which makes them critical for nuclear safety. As the operating time of nuclear power plant increases, not only damage mechanisms but also scaled deposits on steam generator tubes are known to be problematic causing tube support flow hole blockage and heat fouling. The ability to assess the extent and location of scaled deposits on tubes became essential for management and maintenance of steam generator and eddy current bobbin data can be utilized to measure thickness of scale on tubes. In this paper, tube reference standards with various thickness of scaled deposit has been set up to provide information about the overall deposit condition of steam generator tubes, providing essential tool for steam generator management and maintenance to predict and prevent future damages. Also, methodology to automatically measure scale thickness on tubes has been developed and applied to field data to estimate overall scale amount.

  7. A standing pressure wave hypothesis of oscillating forces generated during a steam line break

    International Nuclear Information System (INIS)

    Tinoco, H.

    2001-01-01

    A rapid glance at the figure depicting the net forces acting on the reactor vessel and internals, as obtained through a CFD simulation of a BWR steam line break, reveals an amazing oscillating regularity of these forces which is in glaring contrast to the chaotic behaviour of the steam pressure field in the steam annulus. Assuming that the decompression process excites and maintains standing pressure waves in the annular cylindrical region constituted by the steam annulus, it is possible to reconstruct the net forces acting on the reactor vessel and internals through the contribution of almost only the first dispersive mode. If a Neumann boundary condition is assumed at the section connecting the steam annulus to the steam dome, the frequency predicted is approximately % 5.9 higher than that of the CFD simulations. However, this connecting section allows wave transmission, and a more appropriate boundary condition should be one of the Robin type. Therefore, this section is modelled as an absorbing wall, and the corresponding normal impedance is calculated using the CFD simulations. Week non-linear effects can also be observed in the calculated forces through the presence of the first subharmonic. By the methodology described above, an estimate of the forces acting on the reactor vessel and internals of unit 3 of Forsmark Nuclear Power Plant has been obtained. (author)

  8. Turbulence production by a steam-driven jet in a water vessel

    Energy Technology Data Exchange (ETDEWEB)

    Wissen, R.J.E. van; Schreel, K.R.A.M.; Geld, C.W.M. van der [Eindhoven Univ. of Technology (Netherlands). Dept. of Mechanical Engineering; Wieringa, J. [Unilever Research and Development, Vlaardingen (Netherlands)

    2004-04-01

    Direct steam injection is an efficient means of heating a volume of liquid. Usually the steam is injected via a nozzle, yielding a strong jet that condenses rapidly and transforms into a self-similar single phase jet. In the experiments reported in this paper, superheated steam is injected, centrally, at the bottom of a vertical, cylindrical water vessel. The resulting jet is turbulent (Re=7.9 x 10{sup 4}-18.1 x 10{sup 4} with the length scale based on the width of the jet, r{sub 1/2} and the velocity scale based on the centerline velocity, U{sub 0}). Using PIV in a vertical plane through the central axis, instantaneous velocity fields have been measured at a rate of 15 Hz. Near the inlet, the jet is mainly steam that rapidly condenses. Further downstream, the jet is essentially single phase, although some residual air is present as microscopically small bubbles. In the area directly downstream of the steam part, the ratio of r{sub 1/2} to the vessel radius R (32.5 cm) is about 1/14. The production of turbulent kinetic energy has been quantified for the main process conditions. Its dependencies on temperature, nozzle opening and inlet steam pressure have been determined. This production of energy is related to the stresses exerted on small particles in the mixture, and break-up of particles is discussed. (author)

  9. Process Technology Development of Ni Electroplating in Steam Generator Tube

    International Nuclear Information System (INIS)

    Kim, Joung Soo; Kim, H. P.; Lim, Y. S.; Kim, S. S.; Hwang, S. S.; Yi, Y. S.; Kim, D. J.; Jeong, M. K.

    2009-11-01

    Operating nuclear power steam generator tubing material, Alloy 600, having superior resistance to corrosion has many experiences of damage by various corrosion mechanisms during long term operation period. In this research project, a new Ni electroplating technology to be applied to repair the damaged steam generator tubes has been developed. In this technology development, the optimum conditions for variables affecting the Ni electroplating process, optimum process conditions for maximum adhesion forces at interface between were established. The various mechanical properties (RT and HT tensile, fatigue, creep, burst, etc.) and corrosion properties (general corrosion, pitting, crevice corrosion, stress corrosion cracking, boric acid corrosion, doped steam) of the Ni plated layers made at the established optimum conditions have been evaluated and confirmed to satisfy the specifications. In addition, a new ECT probe developed at KAERI enable to detect defects from magnetic materials was confirmed to be used for Ni electroplated Alloy 600 tubes at the field. For the application of this developed technology to operating plants, a mock-up electroplating system has been designed and manufactured, and set up at Doosan Heavy Industry Co. and also its performance test has been done. At same time, the anode probe has been modified and improved to be used with the established mock-up system without any problem

  10. Control concepts for direct steam generation in parabolic troughs

    Energy Technology Data Exchange (ETDEWEB)

    Valenzuela, Loreto; Zarza, Eduardo [CIEMAT, Plataforma Solar de Almeria, Tabernas (Almeria) (Spain); Berenguel, Manuel [Universidad de Almeria, Dept. de Lenguajes y Computacion, Almeria (Spain); Camacho, Eduardo F. [Universidad de Sevilla, Dept. de Ingenieria de Sistemas y Automatica, Sevilla (Spain)

    2005-02-01

    A new prototype parabolic-trough collector system was erected at the Plataforma Solar de Almeria (PSA) (1996-1998) to investigate direct steam generation (DSG) in a solar thermal power plant under real solar conditions. The system has been under evaluation for efficiency, cost, control and other parameters since 1999. The main objective of the control system is to obtain steam at constant temperature and pressure at the solar field outlet, so that changes in inlet water conditions and/or in solar radiation affect the amount of steam, but not its quality or the nominal plant efficiency. This paper presents control schemes designed and tested for two operating modes, 'Recirculation', for which a proportional-integral-derivative (PI/PID) control functions scheme has been implemented, and 'Once-through', requiring more complex control strategies, for which the scheme is based on proportional-integral (PI), feedforward and cascade control. Experimental results of both operation modes are discussed. (Author)

  11. Rapid Generation of Superheated Steam Using a Water-containing Porous Material

    Science.gov (United States)

    Mori, Shoji; Okuyama, Kunito

    Heat treatment by superheated steam has been utilized in several industrial fields including sterilization, desiccation, and cooking. In particular, cooking by superheated steam is receiving increased attention because it has advantages of reducing the salt and fat contents in foods as well as suppressing the oxidation of vitamin C and fat. In this application, quick startup and cut-off responses are required. Most electrically energized steam generators require a relatively long time to generate superheated steam due to the large heat capacities of the water in container and of the heater. Zhao and Liao (2002) introduced a novel process for rapid vaporization of subcooled liquid, in which a low-thermal-conductivity porous wick containing water is heated by a downward-facing grooved heating block in contact with the upper surface of the wick structure. They showed that saturated steam is generated within approximately 30 seconds from room-temperature water at a heat flux 41.2 kW⁄m2. In order to quickly generate superheated steam of approximately 300°C, which is required for cooking, the heat capacity of the heater should be as small as possible and the imposed heat flux should be so high enough that the porous wick is able to dry out in the vicinity of the contact with the heater and that the resulting heater temperature becomes much higher than the saturation temperature. The present paper proposes a simple structured generator to quickly produce superheated steam. Only a fine wire heater is contacted spirally on the inside wall in a hollow porous material. The start-up, cut-off responses and the rate of energy conversion for input power are investigated experimentally. Superheated steam of 300°C is produced in approximately 19 seconds from room-temperature water for an input power of 300 W. The maximum rate of energy conversion in the steady state is approximately 0.9.

  12. The casebook of technical presentation on a steam generator

    International Nuclear Information System (INIS)

    1986-05-01

    This casebook consists of seven presentations, which are measures and experience of maintenance of water quality in PWR generator, corrosion in steam generator, safely evaluation by management and closing in steam generator, testing of eddy current in steam generator, unsettled problems of safety in steam generator and maintenance of water quality in PWR generator.

  13. 46 CFR 61.15-5 - Steam piping.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Steam piping. 61.15-5 Section 61.15-5 Shipping COAST... Periodic Tests of Piping Systems § 61.15-5 Steam piping. (a) Main steam piping shall be subjected to a... removed and the piping thoroughly examined. (b) All steam piping subject to pressure from the main boiler...

  14. 7 CFR 160.8 - Steam distilled wood turpentine.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Steam distilled wood turpentine. 160.8 Section 160.8... STANDARDS FOR NAVAL STORES General § 160.8 Steam distilled wood turpentine. The designation “steam distilled wood turpentine” shall refer to the kind of spirits of turpentine obtained by steam distillation from...

  15. 49 CFR 229.105 - Steam generator number.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Steam generator number. 229.105 Section 229.105..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Steam Generators § 229.105 Steam generator number. An identification number shall be marked on the steam generator's...

  16. Non-polluting steam generators with fluidized-bed furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Brandes, H [Deutsche Babcock A.G., Oberhausen (Germany, F.R.)

    1979-07-01

    The author reports on a 35 MW steam generator with hard coal fluidized-bed furnace a planned 35 MW steam generator with flotation-dirt fluidized-bed furnace, and on planned steam generators for fluidized-bed firing of hard coal up to a steam power of about 200 MW.

  17. TWR Bench-Scale Steam Reforming Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, D.W.; Soelberg, N.R.

    2003-05-21

    The Idaho Nuclear Technology and Engineering Center (INTEC) was home to nuclear fuel reprocessing activities for decades at the Idaho National Engineering and Environmental Laboratory. As a result of the reprocessing activities, INTEC has accumulated approximately one million gallons of acidic, radioactive, sodium-bearing waste (SBW). The purpose of this demonstration was to investigate a reforming technology, offered by ThermoChem Waste Remediation, LLC, (TWR) for treatment of SBW into a ''road ready'' waste form that would meet the waste acceptance criteria for the Waste Isolation Pilot Plant (WIPP). TWR is the licensee of Manufacturing Technology Conservation International (MTCI) steam-reforming technology in the field of radioactive waste treatment. A non-radioactive simulated SBW was used based on the known composition of waste tank WM-180 at INTEC. Rhenium was included as a non-radioactive surrogate for technetium. Data was collected to determine the nature and characteristics of the product, the operability of the technology, the composition of the off-gases, and the fate of key radionuclides (cesium and technetium) and volatile mercury compounds. The product contained a low fraction of elemental carbon residues in the cyclone and filter vessel catches. Mercury was quantitatively stripped from the product but cesium, rhenium (Tc surrogate), and the heavy metals were retained. Nitrate residues were about 400 ppm in the product and NOx destruction exceeded 86%. The demonstration was successful.

  18. TWR Bench-Scale Steam Reforming Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    D. W. Marshall; N. R. Soelberg

    2003-05-01

    The Idaho Nuclear Technology and Engineering Center (INTEC) was home to nuclear fuel reprocessing activities for decades at the Idaho National Engineering and Environmental Laboratory. As a result of the reprocessing activities, INTEC has accumulated approximately one million gallons of acidic, radioactive, sodium-bearing waste (SBW). The purpose of this demonstration was to investigate a reforming technology, offered by ThermoChem Waste Remediation, LLC, (TWR) for treatment of SBW into a "road ready" waste form that would meet the waste acceptance criteria for the Waste Isolation Pilot Plant (WIPP). TWR is the licensee of Manufacturing Technology Conservation International (MTCI) steam-reforming technology in the field of radioactive waste treatment. A non-radioactive simulated SBW was used based on the known composition of waste tank WM-180 at INTEC. Rhenium was included as a non-radioactive surrogate for technetium. Data was collected to determine the nature and characteristics of the product, the operability of the technology, the composition of the off-gases, and the fate of key radionuclides (cesium and technetium) and volatile mercury compounds. The product contained a low fraction of elemental carbon residues in the cyclone and filter vessel catches. Mercury was quantitatively stripped from the product but cesium, rhenium (Tc surrogate), and the heavy metals were retained. Nitrate residues were about 400 ppm in the product and NOx destruction exceeded 86%. The demonstration was successful.

  19. Characteristics of fluctuating pressure generated in BWR main steam lines

    International Nuclear Information System (INIS)

    Takahashi, Shiro; Okuyama, Keita; Tamura, Akinori

    2009-01-01

    The BWR-3 steam dryer in the Quad Cities Unit 2 Nuclear Power Plant was damaged by high cycle fatigue due to acoustic-induced vibration. The dryer failure was as attributed to flow-induced acoustic resonance at the stub pipes of safety relief valves (SRVs) in the main steam lines (MSLs). The acoustic resonance was considered to be generated by interaction between the sound field and an unstable shear layer across the closed side branches with SRV stub pipes. We have started a research program on BWR dryers to develop their loading evaluation methods. Moreover, it has been necessary to evaluate the dryer integrity of BWR-5 plants which are the main type of BWR in Japan. In the present study, we used 1/10-scale BWR tests and analyses to investigate the flow-induced acoustic resonance and acoustic characteristics in MSLs. The test apparatus consisted of a steam dryer, a steam dome and 4 MSLs with 20 SRV stub pipes. A finite element method (FEM) was applied for the calculation of three-dimensional wave equations in acoustic analysis. We demonstrated that remarkable fluctuating pressures occurred in high and low frequency regions. High frequency fluctuating pressures was generated by the flow-induced acoustic resonance in the SRV stub pipes. Low frequency fluctuating pressure was generated in an MSL with the dead leg. The frequency of the latter almost coincided with the natural frequency of the MSL with the dead leg. The amplitude of the fluctuating pressures in the multiple stub pipes became more intense because of interaction between them compared with that in the single stub pipe. Acoustic analysis results showed that the multiple stub pipes caused several natural frequencies in the vicinity of the natural frequency of the single stub pipe and several modes of the standing wave in the MSLs. (author)

  20. Drying system for steam generators, particularly for steam generators of nuclear power stations

    International Nuclear Information System (INIS)

    Lavalerie, Claude; Borrel, Christian.

    1982-01-01

    A drying system is described which allows for modular construction and which provides a significant available exchange area in a reduced volume. All the drying elements are identical and are distributed according to a ternay circular symmetry and are placed radially and associated to steam guiding facilities which alternately provide around the axis of revolution an output volume of dry steam from one element and an input volume of wet steam in the following element [fr

  1. An Improved Steam Injection Model with the Consideration of Steam Override

    Directory of Open Access Journals (Sweden)

    He Congge

    2017-01-01

    Full Text Available The great difference in density between steam and liquid during wet steam injection always results in steam override, that is, steam gathers on the top of the pay zone. In this article, the equation for steam override coefficient was firstly established based on van Lookeren’s steam override theory and then radius of steam zone and hot fluid zone were derived according to a more realistic temperature distribution and an energy balance in the pay zone. On this basis, the equation for the reservoir heat efficiency with the consideration of steam override was developed. Next, predicted results of the new model were compared with these of another analytical model and CMG STARS (a mature commercial reservoir numerical simulator to verify the accuracy of the new mathematical model. Finally, based on the validated model, we analyzed the effects of injection rate, steam quality and reservoir thickness on the reservoir heat efficiency. The results show that the new model can be simplified to the classic model (Marx-Langenheim model under the condition of the steam override being not taken into account, which means the Marx-Langenheim model is corresponding to a special case of this new model. The new model is much closer to the actual situation compared to the Marx-Langenheim model because of considering steam override. Moreover, with the help of the new model, it is found that the reservoir heat efficiency is not much affected by injection rate and steam quality but significantly influenced by reservoir thickness, and to ensure that the reservoir can be heated effectively, the reservoir thickness should not be too small.

  2. Manpower development for safe operation of nuclear power plant. China. Main steam bypass system operation and maintenance. Task: 6.1.6. Technical report

    International Nuclear Information System (INIS)

    Stubley, P.H.

    1994-01-01

    This mission concentrated on the Steam Bypass system of Qinshan Nuclear Power Plant. The system had experienced spurious opening of the bypass valves, disrupting the steam pressure control and the steam generator level control system. A series of commissioning type tests were defined which should allow the operators to revise the setpoints used in the control of the bypass system, and thus prevent spurious opening while maintaining the desired steam pressure control during power maneuvering. Training also included giving experience from other operating plants on aspects of steam and feedwater systems and components, especially as this experience affected maintenance or gave rise to problems. Steam generated maintenance experience is especially applicable, and a future mission is planned for an expert in this field. In addition other aspects of the Chinese nuclear program was assessed to guide future missions. This included assessment of operating procedures from an availability point of view

  3. Pressure drop, steam content and turbulent cross exchange in water/steam flows

    International Nuclear Information System (INIS)

    Teichel, H.

    1978-01-01

    For describing the behaviour of two-phase flows of water and steam with the help of calculating patterns, a number of empirical correlations are required. - In this article, correlations for the friction pressure drop in water/steam flows are compared, as well as for the steam mass and the volumetric steam content with each other and with the test results on simple geometries. As the mutual effect between cooling chanels plays an important part at the longitudinal flow through bar bundles, the appertaining equations are evaluated, in addition. (orig.) 891 HP [de

  4. Wavelet network controller for nuclear steam generators

    International Nuclear Information System (INIS)

    Habibiyan, H; Sayadian, A; Ghafoori-Fard, H

    2005-01-01

    Poor control of steam generator water level is the main cause of unexpected shutdowns in nuclear power plants. Particularly at low powers, it is a difficult task due to shrink and swell phenomena and flow measurement errors. In addition, the steam generator is a highly complex, nonlinear and time-varying system and its parameters vary with operating conditions. Therefore, it seems that design of a suitable controller is a necessary step to enhance plant availability factor. The purpose of this paper is to design, analyze and evaluate a water level controller for U-tube steam generators using wavelet neural networks. Computer simulations show that the proposed controller improves transient response of steam generator water level and demonstrate its superiority to existing controllers

  5. In service inspection for steam generator tubes

    International Nuclear Information System (INIS)

    Comby, R.; Eyrolles, Ph.

    1988-01-01

    In this paper the authors show the means putting in place for examination of steam generators tubes. These means (eddy current probes, ultrasonic testing) associated with a knowledge on degradation phenomena allow mapping controlled tubes and limiting undesirable obturations [fr

  6. Steam generators for nuclear power plants

    International Nuclear Information System (INIS)

    Tillequin, Jean

    1975-01-01

    The role and the general characteristics of steam generators in nuclear power plants are indicated, and particular types are described according to the coolant nature (carbon dioxide, helium, light water, heavy water, sodium) [fr

  7. US PWR steam generator management: An overview

    International Nuclear Information System (INIS)

    Welty, C.S. Jr.

    1997-01-01

    This paper provides an overview on the status of steam generator management activities in US PWRs, and includes: (1) an overview of the impact of steam generator problems; (2) a brief discussion of historical damage trends and the current damage mechanism of most concern; (3) a discussion of the elements of open-quotes steam generator managementclose quotes; and (4) a description of the approach being followed to implement a degradation-specific protocol for tubing inspection and repair. This paper was prepared in conjunction with another paper presented during the Plenary Session of this Conference, open-quotes Steam Generator Degradation: Current Mitigation Strategies for Controlling Corrosionclose quotes, and is provided as a supplement to that material

  8. Steam Injection For Soil And Aquifer Remediation

    Science.gov (United States)

    The purpose of this Issue Paper is to provide to those involved in assessing remediation technologies for specific sites basic technical information on the use of steam injection for the remediation of soils and aquifers that are contaminated by...

  9. LABORATORY SCALE STEAM INJECTION TREATABILITY STUDIES

    Science.gov (United States)

    Laboratory scale steam injection treatability studies were first developed at The University of California-Berkeley. A comparable testing facility has been developed at USEPA's Robert S. Kerr Environmental Research Center. Experience has already shown that many volatile organic...

  10. ENERGY STAR Certified Commercial Steam Cookers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 1.2 ENERGY STAR Program Requirements for Commercial Steam Cookers that are effective as...

  11. Infrared technique for measuring steam density

    International Nuclear Information System (INIS)

    Snyder, S.C.; Baker, A.G.

    1982-01-01

    A prototype infrared steam densitometer using a two-wavelength, dual-beam technique was developed. Tests were performed on dry steam flows with this technique, which uses two narrow bandwidths of infrared light in the region of 0.9 to 3.0 μm. One wavelength is absorbed by steam, while the other is not. The latter wavelength is used to account for nonabsorptive light losses. In addition to the beam that traverses the steam flow, a reference beam that does not traverse the flow allows the light source to be monitored. The theory of the device is presented, along with a description of the components and of the system's operation. Test results are also presented

  12. Forming a cohesive steam generator maintenance strategy

    International Nuclear Information System (INIS)

    Poudroux, G.

    1991-01-01

    In older nuclear plants, steam generator tube bundles are the most fragile part of the reactor coolant system. Steam generator tubes are subject to numerous types of loading, which can lead to severe degradation (corrosion and wear phenomena). Preventive actions, such as reactor coolant temperature reduction or increasing the plugging limit and their associated analyses, can increase steam generator service life. Beyond these preventive actions, the number of affected tubes and the different locations of the degradations that occur often make repair campaigns necessary. Framatome has developed and qualified a wide range of treatment and repair processes. They enable careful management of the repair campaigns, to avoid reaching the maximum steam generator tube plugging limit, while optimizing the costs. Most of the available repair techniques allow a large number of affected tubes to be treated. Here we look only at those techniques that should be taken into account when defining a maintenance strategy. (author)

  13. CRBRP steam-generator design evolution

    International Nuclear Information System (INIS)

    Geiger, W.R.; Gillett, J.E.; Lagally, H.O.

    1983-01-01

    The overall design of the CRBRP Steam Generator is briefly discussed. Two areas of particular concern are highlighted and considerations leading to the final design are detailed. Differential thermal expansion between the shell and the steam tubes is accommodated by the tubes flexing in the curved section of the shell. Support of the tubes by the internals structure is essential to permit free movement and minimize tube wear. Special spacer plate attachment and tube hole geometry promote unimpeded axial movement of the tubes by allowing individual tubes to rotate laterally and by providing lateral movement of the spacer plates relative to the adjacent support structure. The water/steam heads of the CRBRP Steam Generator are spherical heads welded to the lower and upper tubesheets. They were chosen principally because they provide a positively sealed system and result in more favorable stresses in the tubesheets when compared to mechanically attached steamheads

  14. Reconstruction of steam generators super emergency feadwater supply system (SHNC) and steam dump stations to the atmosphere system PSA

    International Nuclear Information System (INIS)

    Kuzma, J.

    2001-01-01

    Steam Generators Super Emergency Feadwater Supply System (SHNC) and Steam Dump Stations to the Atmosphere System (PSA) are two systems which cooperate to remove residual heat from reactor core after seismic event. SHNC assure feeding of the secondary site of steam generator (Feed) where after heat removal.from primary loops, is relieved to the atmosphere by PSA (Bleed) in form of steam. (author)

  15. Thermodynamics of the silica-steam system

    Energy Technology Data Exchange (ETDEWEB)

    Krikorian, Oscar H [Lawrence Radiation Laboratory, University of California, Livermore, CA (United States)

    1970-05-01

    In most nuclear cratering and cavity formation applications, the working fluid in the expanding cavity consists primarily of vaporized silica and steam. The chemical reaction products of silica and steam under these conditions are not known, although it is known that silica is very volatile in the presence of high-pressure steam under certain geologic conditions and in steam turbines. A review is made of work on the silica-steam system in an attempt to determine the vapor species that exist, and to establish the associated thermo-dynamic data. The review indicates that at 600-900 deg K and 1-100 atm steam pressure, Si(OH){sub 4} is the most likely silicon-containing gaseous species. At 600-900 deg. K and 100-1000 atm steam, Si{sub 2}O(OH){sub 6} is believed to predominate, whereas at 1350 deg K and 2000-9000 atm, a mixture of Si(OH){sub 4} and Si{sub 2}O(OH){sub 6} is consistent with the observed volatilities. In work at 1760 deg. K in which silica was reacted either with steam at 0.5 and 1 atm, or with gaseous mixtures of H{sub 2}/H{sub 2}O and O{sub 2}/H{sub 2}O at 1 atm total pressure, only part of the volatility could be accounted for by Si(OH){sub 4}. Hydrogen was found to greatly enhance the volatility of silica, and oxygen to suppress it. The species most likely to explain this behavior is believed to be SiO(OH). A number of other species may also be significant under these conditions. Thermodynamic data have been estimated for all species considered. The Si-OH bond dissociation energy is found to be {approx}117 kcal/mole in both Si(OH){sub 4} and Si{sub 2}O(OH){sub 6}. (author)

  16. Steam generation at Rihand STPP Stage 1

    Energy Technology Data Exchange (ETDEWEB)

    1987-12-01

    The steam generation plant at Rihand in India has two 500 MW boilers. The boilers are of the balanced draught, single cell, radiant furnace type, and are controlled automatically. Cochran Thermax shell type auxillary steam boilers are used for preheating air to the main boilers and for heating fuel oil during storage and pumping. Electrostatic precipitators and ash handling plants are provided to keep dust and ash within limits. 2 figs.

  17. Steam explosions in light water reactors

    International Nuclear Information System (INIS)

    1981-01-01

    The report deals with a postulated accident caused by molten fuel falling into the lower plenum of the containment of a reactor. The analysis which is presented in the report shows that the thermal energy released in the resulting steam explosion is not enough to destroy the pressure vessel or the containment. The report was prepared for the Swedish Governmental Committee on steam explosion in light water reactors. It includes statements issued by internationally well-known specialists. (G.B.)

  18. Cogeneration steam turbines from Siemens: New solutions

    Science.gov (United States)

    Kasilov, V. F.; Kholodkov, S. V.

    2017-03-01

    The Enhanced Platform system intended for the design and manufacture of Siemens AG turbines is presented. It combines organizational and production measures allowing the production of various types of steam-turbine units with a power of up to 250 MWel from standard components. The Enhanced Platform designs feature higher efficiency, improved reliability, better flexibility, longer overhaul intervals, and lower production costs. The design features of SST-700 and SST-900 steam turbines are outlined. The SST-700 turbine is used in backpressure steam-turbine units (STU) or as a high-pressure cylinder in a two-cylinder condensing turbine with steam reheat. The design of an SST-700 single-cylinder turbine with a casing without horizontal split featuring better flexibility of the turbine unit is presented. An SST-900 turbine can be used as a combined IP and LP cylinder (IPLPC) in steam-turbine or combined-cycle power units with steam reheat. The arrangements of a turbine unit based on a combination of SST-700 and SST-900 turbines or SST-500 and SST-800 turbines are presented. Examples of this combination include, respectively, PGU-410 combinedcycle units (CCU) with a condensing turbine and PGU-420 CCUs with a cogeneration turbine. The main equipment items of a PGU-410 CCU comprise an SGT5-4000F gas-turbine unit (GTU) and STU consisting of SST-700 and SST-900RH steam turbines. The steam-turbine section of a PGU-420 cogeneration power unit has a single-shaft turbine unit with two SST-800 turbines and one SST-500 turbine giving a power output of N el. STU = 150 MW under condensing conditions.

  19. Steam generator in the SNR-project

    International Nuclear Information System (INIS)

    van Westenbrugge, J.K.

    1979-01-01

    The design philosophy of steam generators for 1300 MWe LMFBR's is presented. The basis for this philosophy is the present experience with the licensing of the SNR-300. This experience is reported. The approach for the steam generators for the 1300 MWe LMFBR is elaborated on, both for accident prevention and damage limitation, for the component itself as well as for the system design. Both Design Base Accident and Hypothetical Accidents are discussed. 8 refs

  20. NIST/ASME Steam Properties Database

    Science.gov (United States)

    SRD 10 NIST/ASME Steam Properties Database (PC database for purchase)   Based upon the International Association for the Properties of Water and Steam (IAPWS) 1995 formulation for the thermodynamic properties of water and the most recent IAPWS formulations for transport and other properties, this updated version provides water properties over a wide range of conditions according to the accepted international standards.

  1. New steam generators slated for nuclear units

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This article is a brief discussion of Duke Power's plans to replace steam generators at its McGuire and Catawba nuclear units. A letter of intent to purchase (from Babcock and Wilcox) the 12 Westinghouse steam generators has been signed, but no constructor has been selected at this time. This action is brought about by the failures of more than 3000 tubes in these units

  2. Report of studies on geothermal steam

    Energy Technology Data Exchange (ETDEWEB)

    1954-09-01

    At the time of this report the exploitation of geothermal steam wells was only in the experimental stage. A great deal of information was derived for future use however. The steam is described in terms of its origin and characteristics and the life expectancy of the wells is estimated. Experimental work in Otake, Hakuryu, Beppu and Naruko is described. The power generation station at Larderello, Italy, is discussed. Extensive data from the experimental wells are summarized in tables.

  3. Control system for fluid heated steam generator

    Science.gov (United States)

    Boland, J.F.; Koenig, J.F.

    1984-05-29

    A control system for controlling the location of the nucleate-boiling region in a fluid heated steam generator comprises means for measuring the temperature gradient (change in temperature per unit length) of the heating fluid along the steam generator; means for determining a control variable in accordance with a predetermined function of temperature gradients and for generating a control signal in response thereto; and means for adjusting the feedwater flow rate in accordance with the control signal.

  4. Water-chemistry data for selected springs, geysers, and streams in Yellowstone National Park, Wyoming, 1999-2000

    Science.gov (United States)

    Ball, James W.; McCleskey, R. Blaine; Nordstrom, D. Kirk; Holloway, JoAnn M.; Verplanck, Philip L.; Sturtevant, Sabin A.

    2002-01-01

    Sixty-seven water analyses are reported for samples collected from 44 hot springs and their overflow drainages and two ambient-temperature acid streams in Yellowstone National Park (YNP) during 1990-2000. Thirty-seven analyses are reported for 1999, 18 for June of 2000, and 12 for September of 2000. These water samples were collected and analyzed as part of research investigations in YNP on microbially mediated sulfur oxidation in stream water, arsenic and sulfur redox speciation in hot springs, and chemical changes in overflow drainages that affect major ions, redox species, and trace elements. Most samples were collected from sources in the Norris Geyser Basin. Two ambient-temperature acidic stream systems, Alluvium and Columbine Creeks and their tributaries in Brimstone Basin, were studied in detail. Analyses were performed at or near the sampling site, in an on-site mobile laboratory truck, or later in a USGS laboratory, depending on stability of the constituent and whether or not it could be preserved effectively. Water temperature, specific conductance, pH, Eh, dissolved oxygen (D.O.), and dissolved H2S were determined on-site at the time of sampling. Alkalinity, acidity, and F were determined within a few days of sample collection by titration with acid, titration with base, and ion-selective electrode or ion chromatography (IC), respectively. Concentrations of S2O3 and SxO6 were determined as soon as possible (minutes to hours later) by IC. Concentrations of Br, Cl, NH4, NO2, NO3, SO4, Fe(II), and Fe(total) were determined within a few days of sample collection. Densities were determined later in the USGS laboratory. Concentrations of Li and K were determined by flame atomic absorption spectrometry. Concentrations of Al, As(total), B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe(total), K, Li, Mg, Mn, Na, Ni, Pb, Se, Si, Sr, V, and Zn were determined by inductively-coupled plasma-optical emission spectrometry. Trace concentrations of Cd, Cr, Cu, Pb, and Sb were

  5. Review of the research proposal for the steam generator retired from Kori unit 1

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Joung Soo; Han, Joung Ho; Kim, Hong Pyo; Lim, Yun Soo; Lee, Deok Hyun; Hwang, Seong Sik; Hur, Do Haeng [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2002-03-01

    The tubes of the steam generator retired form Kori unit 1 have many different kinds of failures, such as denting pitting, wastage, ODSCC, PWSCC.Korea Electric Power Research Institute (KEPRI) submitted a research proposal for the steam generator to the Korea Institute S and T Evaluation and Planning (KSITEP). The KISTEP requested Korea Atomic Energy Research Institute to review the proposal by organizing a committee which should be composed of the specialists of the related domestic research institutes. Opinions of the committee on the objectives, research fields, economic benefit and validity in the research proposal were reviewed and suggested optimal research fields to be fulfilled successfully for the retired steam generator. Also, the rolls for the participants in the research works were allocated, which is critical in order to do the project effectively. 6 figs., 5 tabs. (Author)

  6. Fines stabilizing agent reduces production decline rates in steam injected wells

    Energy Technology Data Exchange (ETDEWEB)

    Castillo de Castillo, Milagros; Fernandez Andrades, Jarvi [PDVSA - Petroleos de Venezuela S.A., Caracas (Venezuela); Navarro Cornejo, Willian; Curtis, James [BJ Services do Brasil Ltda., RJ (Brazil)

    2004-07-01

    The Bachaquero Lago heavy oil field, located in Lake Maracaibo, Venezuela, with an area of 9800 ha, in which more than 1800 wells have been drilled. The Lagunillas formation in this field is a mature, clastic, unconsolidated sandstone of Miocene age with good permeability. Clays are present, in laminated form or dispersed within the productive sandstones. Heavy oil, less than 12 deg API, is produced by cyclic steam injection. Wells are completed with cased-hole gravel packs to prevent sand and fines production. Rapid production decline rates are typically observed after the steam injection cycles, due to fines migration and plugging of the reservoir and gravel pack. This paper describes the methodology used to treat the wells with a fines stabilizing agent during the steam injection cycles in order to successfully reduce the subsequent production decline rate. Results from a multi-well pilot project are presented and analyzed. (author)

  7. Development of a steam generator lancing system

    International Nuclear Information System (INIS)

    Jeong, Woo-Tae; Kim, Seok-Tae; Hong, Sung-Yull

    2006-01-01

    It is recommended to clean steam generators of nuclear power plants during plant outages. Under normal operations, sludge is created and constantly accumulates in the steam generators. The constituents of this sludge are different depending on each power plant characteristics. The sludge of the Kori Unit 1 steam generator, for example, was found to be composed of 93% ferrous oxide, 3% carbon and 1% of silica oxide and nickel oxide each. The research to develop a lancing system that would remove sludge deposits from the tubesheet of a steam generator was started in 1998 by the Korea Electric Power Research Institute (KEPRI) of the Korea Electric Power Corporation (KEPCO). The first commercial domestic lancing system in Korea, and KALANS-I Lancing System, was completed in 2000 for Kori Unit 1 for cleaning the tubesheet of its Westinghouse Delta-60 steam generator. Thereafter, the success of the development and site implementation of the KALANS-I lancing system for YGN Units 1 and 2 and Ulchin Units 3 and 4 was also realized in 2004 for sludge removal at those sites. The upper bundle cleaning system for Westinghouse model F steam generators is now under development

  8. Reciprocating wear in a steam environment

    Energy Technology Data Exchange (ETDEWEB)

    Brown, L.J.; Gee, M.G. [National Physical Laboratory, Teddington, Middlesex (United Kingdom)

    2010-07-01

    Tests to simulate the wear between sliding components in steam power plant have been performed using a low frequency wear apparatus at elevated temperatures under static load, at ambient pressure, in a steam environment. The apparatus was modified to accept a novel method of steam delivery. The materials tested were pre-exposed in a flowing steam furnace at temperature for either 500 or 3000 hours to provide some simulation of long term ageing. The duration of each wear test was 50 hours and tests were also performed on as-received material for comparison purposes. Data has been compared with results of tests performed on non-oxidised material for longer durations and also on tests without steam to examine the effect of different environments. Data collected from each test consists of mass change, stub height measurement and friction coefficient as well as visual inspection of the wear track. Within this paper, it is reported that both pre-ageing and the addition of steam during testing clearly influence the friction between material surfaces. (orig.)

  9. Multicomponent seismic reservoir characterization of a steam-assisted gravity drainage (SAGD) heavy oil project, Athabasca oil sands, Alberta

    Science.gov (United States)

    Schiltz, Kelsey Kristine

    Steam-assisted gravity drainage (SAGD) is an in situ heavy oil recovery method involving the injection of steam in horizontal wells. Time-lapse seismic analysis over a SAGD project in the Athabasca oil sands deposit of Alberta reveals that the SAGD steam chamber has not developed uniformly. Core data confirm the presence of low permeability shale bodies within the reservoir. These shales can act as barriers and baffles to steam and limit production by prohibiting steam from accessing the full extent of the reservoir. Seismic data can be used to identify these shale breaks prior to siting new SAGD well pairs in order to optimize field development. To identify shale breaks in the study area, three types of seismic inversion and a probabilistic neural network prediction were performed. The predictive value of each result was evaluated by comparing the position of interpreted shales with the boundaries of the steam chamber determined through time-lapse analysis. The P-impedance result from post-stack inversion did not contain enough detail to be able to predict the vertical boundaries of the steam chamber but did show some predictive value in a spatial sense. P-impedance from pre-stack inversion exhibited some meaningful correlations with the steam chamber but was misleading in many crucial areas, particularly the lower reservoir. Density estimated through the application of a probabilistic neural network (PNN) trained using both PP and PS attributes identified shales most accurately. The interpreted shales from this result exhibit a strong relationship with the boundaries of the steam chamber, leading to the conclusion that the PNN method can be used to make predictions about steam chamber growth. In this study, reservoir characterization incorporating multicomponent seismic data demonstrated a high predictive value and could be useful in evaluating future well placement.

  10. Steam-water jet analysis. Final report

    International Nuclear Information System (INIS)

    Kashiwa, B.A.; Harlow, F.H.; Demuth, R.B.; Ruppel, H.M.

    1984-05-01

    This report presents the results of a theoretical study on the effects of the steam-water jet emitted from a hypothetical rupture in the high-pressure piping pf a nuclear power plant. A set of calculations is presented, incorporating increasingly complex formulations for mass and momentum exchange between the liquid and vapor flow fields. Comparisons between theory and detailed experimental data are given. The study begins with a thorough evaluation of the specification of equilibrium mass and momentum exchange (homogeneous equilibrium) throughout the flow region, a model that generally overpredicts the rate of jet momentum divergence. The study finds that a near-equilibrium momentum exchange rate and a strongly nonequilibrium momentum exchange rate are needed in the region of large vapor-volume fraction to explain the impingement data for fully developed two-phase jets. This leads to the viewpoint that the large-scale jet is characterized by a flow of large liquid entities that travel relatively unaffected by the strongly diverging vapor flow field. The study also finds circumstances in which a persistent core of metastable superheated water can cause much larger impingement pressures than would otherwise be possible. Existing engineering methods are evaluated for jet-loading predictions in plant design. The existing methods appear to be conservative in most possible rupture circumstances with one exception: when the impingement target is about one pipe-diameter away, large enough to capture the full jet, and the rupture flow area is equal to the full pipe flow area, the existing method can produce loadings that are slightly lower than observed for subcooled, flashing discharge. Recommendations have been made to improve the prediction of existing methods under these conditions

  11. Response of the steam generator VVER 1000 to a steam line break

    International Nuclear Information System (INIS)

    Novotny, J.; Novotny, J. Jr.

    2003-01-01

    Dynamic effects of a steam line break in the weld of the steam pipe and the steam collector on the steam generator system are analyzed. Modelling of a steam line break may concern two cases. The steam line without a restraint and the steam line protected by a whip restraint with viscous elements applied at the postulated break cross-section. The second case is considered. Programme SYSTUS offers a special element the stiffness and viscous damping coefficients of which may be defined as dependent on the relative displacement and velocity of its nodes respectively. A circumferential crack is simulated by a sudden decrease of longitudinal and lateral stiffness coefficients of these special SYSTUS elements to zero. The computation has shown that one can simulate the pipe to behave like completely broken during a time interval of 0,0001 s or less. These elements are used to model the whip restraint with viscous elements and viscous dampers of the GERB type as well. In the case of a whip restraint model the stiffness coefficient-displacement relation and damping coefficient - velocity relation are chosen to fit the given characteristics of the restraint. The special SYSTUS elements are used to constitute Maxwell elements modelling the elasto-plastic and viscous properties of the GERB dampers applied to the steam generator. It has been ascertained that a steam line break at the postulated weld crack between the steam pipe and the steam generator collector cannot endanger the integrity of the system even in a case of the absence of a whip restraint effect. (author)

  12. Development of compressible density-based steam explosion simulation code ESE-2

    International Nuclear Information System (INIS)

    Leskovar, M.

    2004-01-01

    A steam explosion is a fuel coolant interaction process by which the energy of the corium is transferred to water in a time-scale smaller than the time-scale for system pressure relief and induces dynamic loading of surrounding structures. A strong enough steam explosion in a nuclear power plant could jeopardize the containment integrity and so lead to a direct release of radioactive material to the environment. To help finding answers on open questions regarding steam explosion understanding and modelling, the steam explosion simulation code ESE-2 is being developed. In contrast to the developed simulation code ESE-1, where the multiphase flow equations are solved with pressure-based numerical methods (best suited for incompressible flow), in ESE-2 densitybased numerical methods (best suited for compressible flow) are used. Therefore ESE-2 will enable an accurate treatment of the whole steam explosion process, which consists of the premixing, triggering, propagation and expansion phase. In the paper the basic characteristics of the mathematical model and the numerical solution procedure in ESE-2 are described. The essence of the numerical treatment is that the convective terms in the multiphase flow equations are calculated with the AUSM+ scheme, which is very time efficient since no field-by-field wave decomposition is needed, using second order accurate discretization. (author)

  13. Steam heating of local well bore area in light crude oil horizons

    Energy Technology Data Exchange (ETDEWEB)

    Mikerin, B P

    1968-02-01

    Beneficial results were obtained from a series of small steam injection treatments of oil producing wells in Asfaltov field. In this field, spacing between producing wells is 200 m, well depth is about 450 m, formation temperature is 27$C, oil gravity is 0,845 g/cu cm, and oil viscosity is 6-10 Hz. In every treatment, 200 g of ''disolvan'' was added per ton of steam, to minimize clay swelling in the formation. Form treatment results it is concluded that: (1) steam stimulation gives positive results 65% of the time; (2) best results were obtained in compact sand formations, 5-6 m thick; (3) positive results last up to one yr after steam soak; (4) with repeated treatments oil production increases 1.5-2 times; (5) temperature of steam during flow from wellhead to well bottom at 350 m, is decreased by 25%; and (6) about 1.3 million kcal were used per 1 m of net sand thickness.

  14. STEAM Enacted: A Case Study of a Middle School Teacher Implementing STEAM Instructional Practices

    Science.gov (United States)

    Herro, Danielle; Quigley, Cassie

    2016-01-01

    This paper examines the implementation practices of a 6th grade middle school teacher enacting STEAM (science, technology, engineering, art and math) teaching in his classroom after participating in a 45-hour STEAM professional development. Case study is used to detail the process, successes, and challenges. Project-based learning, technology…

  15. Synthesis and optimization of steam system networks. 2. Multiple steam levels

    CSIR Research Space (South Africa)

    Price, T

    2010-08-01

    Full Text Available The use of steam in heat exchanger networks (HENs) can be reduced by the application of heat integration with the intention of debottlenecking the steam boiler and indirectly reducing the water requirement [Coetzee and Majozi. Ind. Eng. Chem. Res...

  16. Cleaning device for steam units in a nuclear power plant

    International Nuclear Information System (INIS)

    Sasamuro, Takemi.

    1978-01-01

    Purpose: To prevent radioactive contamination upon dismantling and inspection of steam units such as a turbine to a building containing such units and the peripheral area. Constitution: A steam generator indirectly heated by steam supplied from steam generating source in a separate system containing no radioactivity is provided to produce cleaning steam. A cleaning steam pipe is connected by way of a stop valve between separation valve of a nuclear power plant steam pipe and a high pressure turbine. Upon cleaning, the separation valve is closed, and steam supplied from the cleaning steam pipe is flown into a condenser. The water thus condensated is returned by way of a feed water heater and a condenser to a water storage tank. (Nakamura, S.)

  17. Flux and genesis of CO2 degassing from volcanic-geothermal fields of Gulu-Yadong rift in the Lhasa terrane, South Tibet: Constraints on characteristics of deep carbon cycle in the India-Asia continent subduction zone

    Science.gov (United States)

    Zhang, Lihong; Guo, Zhengfu; Sano, Yuji; Zhang, Maoliang; Sun, Yutao; Cheng, Zhihui; Yang, Tsanyao Frank

    2017-11-01

    Gulu-Yadong rift (GYR) is the longest extensional, NE-SW-trending rift in the Himalayas and Lhasa terrane of South Tibet. Many volcanic-geothermal fields (VGFs), which comprise intense hot springs, steaming fissures, geysers and soil micro-seepage, are distributed in the GYR, making it ideal area for studying deep carbon emissions in the India-Asia continent subduction zone. As for the northern segment of GYR in the Lhasa terrane, its total flux and genesis of CO2 emissions are poorly understood. Following accumulation chamber method, soil CO2 flux survey has been carried out in VGFs (i.e., Jidaguo, Ningzhong, Sanglai, Tuoma and Yuzhai from south to north) of the northern segment of GYR. Total soil CO2 output of the northern GYR is about 1.50 × 107 t a-1, which is attributed to biogenic and volcanic-geothermal source. Geochemical characteristics of the volcanic-geothermal gases (including CO2 and He) of the northern GYR indicate their significant mantle-derived affinities. Combined with previous petrogeochemical and geophysical data, our He-C isotope modeling calculation results show that (1) excess mantle-derived 3He reflects degassing of volatiles related with partial melts from enriched mantle wedge induced by northward subduction of the Indian lithosphere, and (2) the crust-mantle interaction can provide continuous heat and materials for the overlying volcanic-geothermal system, in which magma-derived volatiles are inferred to experience significant crustal contamination during their migration to the surface.

  18. Sound propagation in the steam generator - A theoretical approach

    International Nuclear Information System (INIS)

    Heckl, M.

    1990-01-01

    In order to assess the suitability of acoustic tomography in the steam generator, detailed information on its acoustic transmission properties is needed. We have developed a model which allows one to calculate the sound field produced by an incident wave in the steam generator. In our model we consider the steam generator as a medium consisting of a two-dimensional array of infinitely long cylindrical tubes. They are thin-walled, made of metal and are immersed in a liquid. Inside them there is a liquid or a gas. The incident wave is plane and perpendicular to the cylindrical tubes. When a sound wave crosses the tube bundle, each individual tube is exposed to a fluctuating pressure field and scatters sound which, together with the incident wave, influences the pressure at all surrounding tubes. The motion of an individual tube is given by differential equations (Heckl 1989) and the pressure difference between inside and outside. The interaction of a tube wall with the fluid inside and outside is treated by imposing suitable boundary conditions. Since the cylinder array is periodic, it can be considered as consisting of a large number of tube rows with a constant distance between adjacent cylinders within a row and constant spacing of the rows. The sound propagates from row to row, each time getting partly transmitted and partly reflected. A single row is similar to a diffraction grating known from optics. The transmission properties of one row or grating depend on the ratio between spacing and wavelength. If the wavelength is larger than the spacing, then the wave is transmitted only in the original direction. However, for wavelengths smaller than the spacing, the transmitted wave has components travelling in several discrete directions. The response of one row to sound scattered from a neighbouring row is calculated from Kirchhoff's theorem. An iteration scheme has been developed to take the reflection and transmission at several rows into account. 7 refs, figs and

  19. Numerical simulation of dryout and post-dryout heat transfer in a straight-pipe once-through steam generator

    International Nuclear Information System (INIS)

    Shi, Jianxin; Sun, Baozhi; Han, Wenjing; Zhang, Guolei; Li, Yanjun; Yang, Longbin

    2016-01-01

    Highlights: • Two-fluid three-flow-field model is developed to predict dryout in steam generator. • The empirical correlation is used to correct dryout criterion. • The interactions between three-flow-fields and the wall are considered. • Dryout and post-dryout heat transfer mechanisms are discussed through the results. - Abstract: Accurately predicting dryout and post-dryout heat transfer characteristics is critical for proper design of once-through steam generators. This paper provides a reasonable and simple method for this prediction by introducing a two-fluid, three-flow-field mathematical model and improving the dryout criterion-critical quality, and conducts a numerical simulation of dryout and post-dryout heat transfer in a once-through steam generator to prove the model’s performance. The results show that the critical quality in a once-through steam generator is about 0.82, with the heat transfer capacity significantly reducing and the wall temperature sharply increasing in a non-linear form by approximately 30 K when dryout occurs. Part of the steam is superheated in the post-dryout region, resulting in a deviation from thermodynamic equilibrium between the vapor and liquid phases. Dryout and post-dryout heat transfer in the once-through steam generator operate between complete deviation from thermodynamic equilibrium and complete thermodynamic equilibrium. Therefore, the presence of droplets has a significant influence on the mass, momentum and energy transfer between the film and vapor phases.

  20. Investor Outlook: Gene Therapy Picking up Steam; At a Crossroads.

    Science.gov (United States)

    Schimmer, Joshua; Breazzano, Steven

    2016-09-01

    The gene therapy field continues to pick up steam with recent successes in a number of different therapeutic indications that highlight the potential for the platform. As the field continues to make progress, a growing data set of long-term safety and efficacy data will continue to define gene therapy's role, determining ultimately how widely it may be used beyond rare, serious diseases with high unmet needs. New technologies often take unanticipated twists and turns as patient exposure accumulates, and gene therapy may be no exception. That said, with many diseases that have no other treatment options beyond gene therapy and that present considerable morbidity and mortality, the field appears poised to withstand some minor and even major bumps in the road should they emerge.

  1. Control scheme for direct steam generation in parabolic troughs under recirculation operation mode

    Energy Technology Data Exchange (ETDEWEB)

    Valenzuela, L.; Zarza, E. [CIEMAT, Plataforma Solar de Almeria, Ctra. Senes s/n, P.O. Box 22, E-04200 Tabernas, Almeria (Spain); Berenguel, M. [Universidad de Almeria, Dpto. Lenguajes y Computacion, Ctra. Sacramento s/n, E-04120 Almeria (Spain); Camacho, E.F. [Universidad de Sevilla, Dpto. de Ingenieria de Sistemas y Automatica, Camino de los Descubrimientos s/n, E-41092 Sevilla (Spain)

    2006-01-15

    Electricity production using solar thermal energy is one of the main research areas at present in the field of renewable energies, these systems being characterised by the need of reliable control systems aimed at maintaining desired operating conditions in the face of changes in solar radiation, which is the main source of energy. A new prototype of solar system with parabolic trough collectors was implemented at the Plataforma Solar de Almeria (PSA, South-East Spain) to investigate the direct steam generation process under real solar conditions in the parabolic solar collector field of a thermal power plant prototype. This paper presents details and some results of the application of a control scheme designed and tested for the recirculation operation mode, for which the main objective is to obtain steam at constant temperature and pressure at the outlet of the solar field, so that changes produced in the inlet water conditions and/or solar radiation will only affect the amount of steam produced by the solar field. The steam quality and consequently the nominal efficiency of the plant are thus maintained. (author)

  2. Darlington steam generator life assurance program

    International Nuclear Information System (INIS)

    Jelinski, E.; Dymarski, M.; Maruska, C.; Cartar, E.

    1995-01-01

    The Darlington Nuclear Generating Station belonging to Ontario Hydro is one of the most modern and advanced nuclear generating stations in the world. Four reactor units each generate 881 net MW, enough to provide power to a major city, and representing approximately 20% of the Ontario grid. The nuclear generating capacity in Ontario represents approximately 60% of the grid. In order to look after this major asset, many proactive preventative and predictive maintenance programs are being put in place. The steam generators are a major component in any power plant. World wide experience shows that nuclear steam generators require specialized attention to ensure reliable operation over the station life. This paper describes the Darlington steam generator life assurance program in terms of degradation identification, monitoring and management. The requirements for chemistry control, surveillance of process parameters, surveillance of inspection parameters, and the integration of preventative and predictive maintenance programs such as water lancing, chemical cleaning, RIHT monitoring, and other diagnostics to enhance our understanding of life management issues are identified and discussed. We conclude that we have advanced proactive activities to avoid and to minimize many of the problems affecting other steam generators. An effective steam generator maintenance program must expand the knowledge horizon to understand life limiting processes and to analyze and synthesize observations with theory. (author)

  3. Radiation heat transfer within and from high temperature plumes composed of steam and molten nuclear debris

    International Nuclear Information System (INIS)

    Condiff, D.W.

    1987-03-01

    The Differential Approximation of Radiation Heat Transfer which includes anisotropic scattering is formulated to account for multiple source and temperature fields of multiphase flow. The formulation is applied to a simplified model of a plume consisting of high temperature emissive particles in steam at parametrically variable lower temperatures. Parametric model calculations are presented which account for spectral emission and absorption by steam using a band approximation as well as emission, absorption and scattering by the debris. The results are found to be far more sensitive to emission properties of individual particles, than to their scattering properties at high temperatures

  4. Electropolishing of replacement steam generator channel heads at Millstone-2 PWR

    International Nuclear Information System (INIS)

    Hudson, M.J.B.; Raney, H.; Raney, D.; Spalaris, C.N.

    1992-07-01

    A field application of EPRI-developed steam generator electropolishing technique was performed at Millstone-2 PWR. The process was qualified under previous programs on a laboratory scale, but it was thought appropriate to scale up application to full size components. Replacement of steam generators at Millstone-2 provided a unique opportunity to demonstrate that electropolishing can be applied safely and at a cost which was judged to be recoverable after a small number of fuel cycles. The project, preparation, electropolishing and cleanup, was completed at the reactor site in 25 working days. An alternate, less costly electrolyte solution was qualified for use in future applications

  5. Study with a steam tracer in a zone near well Az-64, in the Los Azufres geothermal field, Mich.; Estudio con un trazador de vapor en la zona aledana al pozo Az-64, en el campo geotermico de Los Azufres, Mich.

    Energy Technology Data Exchange (ETDEWEB)

    Iglesias, Eduardo R. [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: iglesias@iie.org.mx; Flores Armenta, Magaly; Quijano Leon, Jose Luis; Torres Rodriguez, Marco A. [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico); Torres, Rodolfo J.; Reyes Picasso, Neftali [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Sandoval Medina, Fernando [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico)

    2009-01-15

    A previous tracer study in the Maritaro-La Cumbre area of the Los Azufres, Mich., geothermal field concluded that injection in well Az-15 recharges a group of producing wells located east of the injector to a maximum distance of about 2000 m. The study also indicated injection in Az-15 either does not recharge wells farther east in the neighborhood of the Laguna Verde fault, or does so at very low rates over a long period. Because it is important to recharge this zone, it was decided to explore the possibility of doing it by injecting in well Az-64, located in the area. Thus the present study was designed. Six producing wells were chosen to monitor tracer arrivals. Because all the chosen wells produce steam (several also produce water) and for economic reasons, it was decided to use a steam-phase tracer. We chose sulfur hexafluoride (SF6), a tracer successfully used before in the field. On October 24, 2006, we injected 96.4 kg of SF6 into well Az-64. All six chosen wells were sampled for 156 days, starting the day of injection. The tracer was detected in all six wells and for every well the shape of the residence curve clearly depicted the fractured nature of the corresponding permeability. Again in every case, the recovery curves indicated recovery was completed within the 156-day sampling period. The largest recoveries were in wells Az-05 (48.5%) and Az-43 (1.27%), those closest to the injection well and on the same side of the Maritaro fault as Az-64. Well Az-51, lying at 848 m from the injector and farthest away, registered the third-highest recovery percentage (1.01 x 10-5%), significantly higher than well Az-19 (6.95 x 10-6%), located 490 m from the injector; the two wells are on the same side of the Maritaro fault as Az-64. Well Az-32, located 423 m from the injector, but on the other side of the Maritaro fault, recovered 5.6 x 10-7% of the injected tracer, comparable to 8.67 x 10-7%, the amount recovered in well Az-13 on the same side of the Maritaro fault

  6. Risk-based and maintenance systems for steam turbines

    International Nuclear Information System (INIS)

    Fujiyama, K.; Nagai, S.; Akikuni, Y.; Fujiwara, T.; Furuya, K.; Matsumoto, S.; Takagi, K.; Kawabata, T.

    2003-01-01

    The risk-based maintenance (RBM) system has been developed for steam turbine plants coupled with the quick inspection systems. The RBM system utilizes the field failure and inspection database accumulated over 30 years. The failure modes are determined for each component of steam turbines and the failure scenarios are described as event trees. The probability of failure is expressed in the form of unreliability functions of operation hours or start-up cycles through the cumulative hazard function method. The posterior unreliability is derived from the field data analysis according to the inspection information. Quick inspection can be conducted using air-cooled borescope and heat resistant ultrasonic sensors even if the turbine is not cooled down sufficiently. Another inspection information comes from degradation and damage measurement. The probabilistic life assessment using structural analysis and statistical material properties, the latter is estimated from hardness measurement, replica observation and embrittlement measurement. The risk function is calculated as the sum product of unreliability functions and expected monetary loss as the consequence of failure along event trees. The optimum maintenance plan is determined among simulated scenarios described through component breakdown trees, life cycle event trees and risk functions. Those methods are effective for total condition assessment and economical maintenance for operating plants. (orig.)

  7. Risk-based inspection and maintenance systems for steam turbines

    International Nuclear Information System (INIS)

    Fujiyama, Kazunari; Nagai, Satoshi; Akikuni, Yasunari; Fujiwara, Toshihiro; Furuya, Kenichiro; Matsumoto, Shigeru; Takagi, Kentaro; Kawabata, Taro

    2004-01-01

    The risk-based maintenance (RBM) system has been developed for steam turbine plants coupled with the quick inspection systems. The RBM system utilizes the field failure and inspection database accumulated over 30 years. The failure modes are determined for each component of steam turbines and the failure scenarios are described as event trees. The probability of failure is expressed in the form of unreliability functions of operation hours or start-up cycles through the cumulative hazard function method. The posterior unreliability is derived from the field data analysis according to the inspection information. Quick inspection can be conducted using air-cooled borescope and heat resistant ultrasonic sensors even if the turbine is not cooled down sufficiently. Another inspection information comes from degradation and damage measurement. The probabilistic life assessment using structural analysis and statistical material properties, the latter is estimated from hardness measurement, replica observation and embrittlement measurement. The risk function is calculated as the sum product of unreliability functions and expected monetary loss as the consequence of failure along event trees. The optimum maintenance plan is determined among simulated scenarios described through component breakdown trees, life cycle event trees and risk functions. Those methods are effective for total condition assessment and economical maintenance for operating plants

  8. Particle Swarm Optimization to the U-tube steam generator in the nuclear power plant

    International Nuclear Information System (INIS)

    Ibrahim, Wesam Zakaria

    2014-01-01

    Highlights: • We establish stability mathematical model of steam generator and reactor core. • We propose a new Particle Swarm Optimization algorithm. • The algorithm can overcome premature phenomenon and has a high search precision. • Optimal weight of steam generator is 15.1% less than the original. • Sensitivity analysis and optimal design provide reference for steam generator design. - Abstract: This paper, proposed an improved Particle Swarm Optimization approach for optimize a U-tube steam generator mathematical model. The UTSG is one of the most important component related to safety of most of the pressurized water reactor. The purpose of this article is to present an approach to optimization in which every target is considered as a separate objective to be optimized. Multi-objective optimization is a powerful tool for resolving conflicting objectives in engineering design and numerous other fields. One approach to solve multi-objective optimization problems is the non-dominated sorting Particle Swarm Optimization. PSO was applied in regarding the choice of the time intervals for the periodic testing of the model of the steam generator

  9. Particle Swarm Optimization to the U-tube steam generator in the nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, Wesam Zakaria, E-mail: mimi9_m@yahoo.com

    2014-12-15

    Highlights: • We establish stability mathematical model of steam generator and reactor core. • We propose a new Particle Swarm Optimization algorithm. • The algorithm can overcome premature phenomenon and has a high search precision. • Optimal weight of steam generator is 15.1% less than the original. • Sensitivity analysis and optimal design provide reference for steam generator design. - Abstract: This paper, proposed an improved Particle Swarm Optimization approach for optimize a U-tube steam generator mathematical model. The UTSG is one of the most important component related to safety of most of the pressurized water reactor. The purpose of this article is to present an approach to optimization in which every target is considered as a separate objective to be optimized. Multi-objective optimization is a powerful tool for resolving conflicting objectives in engineering design and numerous other fields. One approach to solve multi-objective optimization problems is the non-dominated sorting Particle Swarm Optimization. PSO was applied in regarding the choice of the time intervals for the periodic testing of the model of the steam generator.

  10. Thermohydraulic verification during THTR steam generator commissioning

    International Nuclear Information System (INIS)

    Henry, C.; Elter, C.

    1988-01-01

    In one of the six THTR 300 steam generators thermocouples are installed inside the heat transfer tube bundles for measuring the gas and steam temperatures. Fluid temperature distribution measurements along and across the helix bundle have been recorded in its first months of operation over a load range of 40% up to 100% for steady state and transient conditions. Using these measurements as well as the rest of the operating instrumentation. the computer programs for the design of heat exchanger heat transfer areas are verified. The temperature measurements for steady state conditions are compared with predictions obtained in the design stage. In these codes. the heat transferred from the outside helium gas to the water/steam inside the tubes is determined in discrete steps along the heating surface by one- and two-phase heat transfer correlations. The degree of conformity between prediction and measurement is discussed and compared with more recent correlations. (author)

  11. Structural integrity analysis of a steam turbine

    International Nuclear Information System (INIS)

    Villagarcia, Maria P.

    1997-01-01

    One of the most critical components of a power utility is the rotor of the steam turbine. Catastrophic failures of the last decades have promoted the development of life assessment procedures for rotors. The present study requires the knowledge of operating conditions, component geometry, the properties of materials, history of the component, size, location and nature of the existing flaws. The aim of the present work is the obtention of a structural integrity analysis procedure for a steam turbine rotor, taking into account the above-mentioned parameters. In this procedure, a stress thermal analysis by finite elements is performed initially, in order to obtain the temperature and stress distribution for a subsequent analysis by fracture mechanics. The risk of a fast fracture due to flaws in the central zone of the rotor is analyzed. The procedure is applied to an operating turbine: the main steam turbine of the Atucha I nuclear power utility. (author)

  12. Steam explosions in sodium cooled breeder reactors

    International Nuclear Information System (INIS)

    Lundell, B.

    1982-01-01

    Steam explosion is considered a physical process which transport heat from molten fuel to liquid coolant so fast that the coolant starts boiling in an explosion-like manner. The arising pressure waves transform part of the thermal energy to mechanical energy. This can stress the reactor tank and threaten its hightness. The course of the explosion has not been theoretical explained. Experimental results indicate that the probability of steam explosions in a breeder reactor is small. The efficiency of the transformation of the heat of fusion into mechanical energy in substantially lower than the theoretical maximum value. The mechanical stress from the steam explosion on the reactor tank does not seem to jeopardize its tightness. (G.B.)

  13. Chemical cleaning of nuclear (PWR) steam generators

    International Nuclear Information System (INIS)

    Welty, C.S. Jr.; Mundis, J.A.

    1982-01-01

    This paper reports on a significant research program sponsored by a group of utilities (the Steam Generator Owners Group), which was undertaken to develop a process to chemically remove corrosion product deposits from the secondary side of pressurized water reactor (PWR) power plant steam generators. Results of this work have defined a process (solvent system and application methods) that is capable of removing sludge and tube-to-tube support plate crevice corrosion products generated during operation with all-volatile treatment (AVT) water chemistry. Considers a plant-specific test program that includes all materials in the steam generator to be cleaned and accounts for the physical locations (proximity and contact) of those materials. Points out that prior to applying the process in an operational unit, the utility, with the participation of the NSSR vendor, must define allowable total corrosion to the materials of construction of the unit

  14. New ferritic steels for advanced steam plants

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, K.H; Koenig, H. [GEC ALSTHOM Energie GmbH, Nuremberg (Germany)

    1998-12-31

    During the last 15-20 years ferritic-martensitic 9-12 % chromium steels have been developed under international research programmes which permit inlet steam temperatures up to approx. 625 deg C and pressures up to about 300 bars, thus leading to improvements in thermal efficiency of around 8 % and a CO{sub 2} reduction of about 20 % versus conventional steam parameters. These new steels are already being applied in 13 European and 34 Japanese power stations with inlet steam temperature up to 610 deg C. This presentation will give an account of the content, scope and results of the research programmes and of the experience gained during the production of components which have been manufactured from the new steels. (orig.) 13 refs.

  15. A steam separator-superheater apparatus

    International Nuclear Information System (INIS)

    Androw, Jean; Bessouat, Roger; Peyrelongue, J.-P.

    1973-01-01

    Description is given of a separator-superheater apparatus comprising an outer enclosure containing a separating-unit and a steam superheating unit according to the main patent. The present addition relates to an improvement in that apparatus, characterized in that the separating unit and the superheating unit, mounted in two distinct portions of the outer enclosure, are divided into the same number of sub-units of each unit being identical and operating in parallel, and in that to each separator sub-unit is associated a superheater sub-unit, said sub-units being mounted in series and located in one in the other of the enclosure two portions, respectively. This can be applied to the treatment of the exhaust steam of a turbine high pressure body, prior to re-injecting said steam into the low pressure body [fr

  16. New ferritic steels for advanced steam plants

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, K H; Koenig, H [GEC ALSTHOM Energie GmbH, Nuremberg (Germany)

    1999-12-31

    During the last 15-20 years ferritic-martensitic 9-12 % chromium steels have been developed under international research programmes which permit inlet steam temperatures up to approx. 625 deg C and pressures up to about 300 bars, thus leading to improvements in thermal efficiency of around 8 % and a CO{sub 2} reduction of about 20 % versus conventional steam parameters. These new steels are already being applied in 13 European and 34 Japanese power stations with inlet steam temperature up to 610 deg C. This presentation will give an account of the content, scope and results of the research programmes and of the experience gained during the production of components which have been manufactured from the new steels. (orig.) 13 refs.

  17. Steam chugging in pressure suppression containment

    International Nuclear Information System (INIS)

    Lee, C.K.B.; Chan, C.K.

    1978-01-01

    The condensation of steam flow in subcooled water was studied by injecting a quasi-steady stream of saturated steam into a pool water at different temperature. From the movies, it was observed that chugging occurred at a frequency on the order of 1 to 2 times a second. In between each chug over a period of approximately half a second, a few bubbles formed and collapsed at the exit of the downcomer. At a mass flow rate of approximately 5.02 Kg/m 2 sec., the chugging process is found to be strongly affected by the bubble formation. At pool temperatures below 50 0 C, the chugging process is dominated by internal chugging which is characterized by high water slug exit velocity, detached steam bubble and lhigh chugging level. Above 50 0 C, the external chugging mode is dominant. The external chugging mode is characterized by pancake bubble shape, low water slug exit velocity, and low chugging level. (author)

  18. Development of steam generator manufacturing technology

    International Nuclear Information System (INIS)

    Grant, J.A.

    1979-01-01

    In 1968 Babcock and Wilcox (Operations) Ltd., received an order from the CEGB to design, manufacture, install and commission 16 Steam Generators for 2 x 660 Mw (e) Advanced Gas Cooled Reactor Power Station at Hartlepool. This order was followed in 1970 by a similar order for the Heysham Power Station. The design and manufacture of the Steam Generators represented a major advance in technology and the paper discusses the methods by which a manufacturing facility was developed, by the Production Division of Babcock, to produce components to a quality, complexity and accuracy unique in the U.K. commercial boilermaking industry. The discussion includes a brief design background, a description of the Steam Generators and a view of the Production Division background. This is followed by a description of the organisation of the technological development and a consideration of the results. (author)

  19. Monitoring the efficacy of steam and formaldehyde treatment of naturally Salmonella-infected layer houses

    DEFF Research Database (Denmark)

    Gradel, K.O.; Jørgensen, J.C.; Andersen, J.S.

    2004-01-01

    steam treated in a download period, aiming at greater than or equal to60degreesC and 100% relative humidity (RH) during a 24-h period, with or without the addition of 30 ppm formaldehyde. In addition, two control layer houses were disinfected chemically. Salmonella samples taken from predetermined sites...... before and after treatment were tested qualitatively for Salmonella and coliforms. Samples with indicator bacteria (feed inoculated with Escherichia coli or Enterococcus faecalis and faeces with naturally occurring E. coli and enterococci) were placed during steam-treatment at 12 sites in each house...... (where the temperature was logged at 5-min intervals) and tested for surviving bacteria. Generally, the field test results confirmed the results of laboratory tests, especially when 30 ppm formaldehyde was added to the steam. In well-sealed houses, the recommended temperature-humidity-time scheme...

  20. Proceedings of the third international steam generator and heat exchanger conference

    International Nuclear Information System (INIS)

    1998-01-01

    The Third International Steam Generator and Heat Exchanger conference had the objective to present the state of knowledge of steam generator performance and life management, and also heat exchanger technology. As this conference followed on from the previous conferences held in Toronto in 1990 and 1994, the emphasis was on recent developments, particularly those of the last 4 years. The conference provided an opportunity to operators, designers and researchers in the field of steam generation associated with electricity generation by nuclear energy to present their findings and exchange ideas. The conference endeavoured to do this over the widest possible range of subject areas, including: general operating experience, life management and fitness for service strategies, maintenance and inspection, thermalhydraulics, vibration, fretting and fatigue, materials, chemistry and corrosion and the regulatory issues

  1. Proceedings of the third international steam generator and heat exchanger conference

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-07-01

    The Third International Steam Generator and Heat Exchanger conference had the objective to present the state of knowledge of steam generator performance and life management, and also heat exchanger technology. As this conference followed on from the previous conferences held in Toronto in 1990 and 1994, the emphasis was on recent developments, particularly those of the last 4 years. The conference provided an opportunity to operators, designers and researchers in the field of steam generation associated with electricity generation by nuclear energy to present their findings and exchange ideas. The conference endeavoured to do this over the widest possible range of subject areas,including: general operating experience, life management and fitness for service strategies, maintenance and inspection, thermalhydraulics, vibration, fretting and fatigue, materials, chemistry and corrosion and the regulatory issues.

  2. Effects of shutdown chemistry on steam generator radiation levels at Point Beach Unit 2. Interim report

    International Nuclear Information System (INIS)

    Kormuth, J.W.

    1982-05-01

    A refueling shutdown chemistry test was conducted at a PWR, Point Beach Unit 2. The objective was to yield reactor coolant chemistry data during the cooldown/shutdown process which might establish a relationship between shutdown chemistry and its effects on steam generator radiation fields. Of particular concern were the effects of the presence of hydrogen in the coolant as contrasted to an oxygenated coolant. Analysis of reactor coolant samples showed a rapid soluble release (spike) in Co-58, Co-60, and nickel caused by oxygenation of the coolant. The measurement of radioisotope specific activities indicates that the material undergoing dissolution during the shutdown originated from different sources which had varying histories of activation. The test program developed no data which would support theories that oxygenation of the coolant while the steam generators are full of water contributes to increased steam generator radiation levels

  3. How to compute the power of a steam turbine with condensation, knowing the steam quality of saturated steam in the turbine discharge

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez Albarran, Manuel Jaime; Krever, Marcos Paulo Souza [Braskem, Sao Paulo, SP (Brazil)

    2009-07-01

    To compute the power and the thermodynamic performance in a steam turbine with condensation, it is necessary to know the quality of the steam in the turbine discharge and, information of process variables that permit to identifying with high precision the enthalpy of saturated steam. This paper proposes to install an operational device that will expand the steam from high pressure point on the shell turbine to atmosphere, both points with measures of pressure and temperature. Arranging these values on the Mollier chart, it can be know the steam quality value and with this data one can compute the enthalpy value of saturated steam. With the support of this small instrument and using the ASME correlations to determine the equilibrium temperature and knowing the discharge pressure in the inlet of surface condenser, the absolute enthalpy of the steam discharge can be computed with high precision and used to determine the power and thermodynamic efficiency of the turbine. (author)

  4. Modelling of steam condensation in the primary flow channel of a gas-heated steam generator

    International Nuclear Information System (INIS)

    Kawamura, H.; Meister, G.

    1982-10-01

    A new simulation code has been developed for the analysis of steam ingress accidents in high temperatures reactors which evaluates the heat transfer in a steam generator headed by a mixture of helium and water steam. Special emphasis is laid on the analysis of steam condensation in the primary circuit of the steam generator. The code takes wall and bulk condensation into account. A new method is proposed to describe the entrainment of water droplets in the primary gas flow. Some typical results are given. Steam condensation in the primary channel may have a significant effect on temperature distributions. The effect on the heat transferred by the steam generator, however, is found to be not so prominent as might be expected. The reason is discussed. A simplified code will also be described, which gives results with reasonable accuracy within much shorter execution times. This code may be used as a program module in a program simulating the total primary circuit of a high temperature reactor. (orig.) [de

  5. Steam separator-superheater with drawing of a fraction of the dried steam

    International Nuclear Information System (INIS)

    Bessouat, Roger; Marjollet, Jacques.

    1976-01-01

    This invention concerns a vertical separator-superheater of the steam from a high pressure expansion turbine before it is admitted to an expansion turbine at a lower pressure, by heat exchange with steam under a greater pressure, and drawing of a fraction of the dried steam before it is superheated. Such drawing off is necessary in the heat exchange systems of light water nuclear reactors. Its purpose is to provide a separator-superheater that provides an even flow of non superheated steam and a regular distribution of the steam to be superheated to the various superheating bundles, with a significantly uniform temperature of the casing, thereby preventing thermal stresses and ensuring a minimal pressure drop. The vertical separator-superheater of the invention is divided into several vertical sections comprising as from the central area, a separation area of the steam entrained water and a superheater area and at least one other vertical section with only a separation area of the steam entrained water [fr

  6. Coupled simulation of steam line break accident

    International Nuclear Information System (INIS)

    Royer, E.; Raimond, E.; Caruge, D.

    2000-01-01

    The steam line break is a PWR type reactor design accident, which concerns coupled physical phenomena. To control these problems simulation are needed to define and validate the operating procedures. The benchmark OECD PWR MSLB (Main Steam Line Break) has been proposed by the OECD to validate the feasibility and the contribution of the multi-dimensional tools in the simulation of the core transients. First the benchmark OECD PWR MSLB is presented. Then the analysis of the three exercises (system with pinpoint kinetic, three-dimensional core and whole system with three-dimensional core) are discussed. (A.L.B.)

  7. Fourth international seminar on horizontal steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Tuomisto, H. [ed.] [IVO Group, Vantaa (Finland); Purhonen, H. [ed.] [VTT, Espoo (Finland); Kouhia, V. [ed.] [Lappeenranta Univ. of Technology (Finland)

    1997-12-31

    The general objective of the International Seminars of Horizontal Steam Generator Modelling has been the improvement in understanding of realistic thermal hydraulic behaviour of the generators when performing safety analyses for VVER reactors. The main topics presented in the fourth seminar were: thermal hydraulic experiments and analyses, primary collector integrity, feedwater distributor replacement, management of primary-to-secondary leakage accidents and new developments in the VVER safety technology. The number of participants, representing designers and manufacturers of the horizontal steam generators, plant operators, engineering companies, research organizations, universities and regulatory authorities, was 70 from 10 countries.

  8. Corrosion problems in PWR steam generators

    International Nuclear Information System (INIS)

    Weber, J.; Suery, P.

    1976-01-01

    Examinations on pulled steam generator tubes from the Swiss nuclear power plants Beznau I and II, together with some laboratory tests, may be summarized as follows: Corrosion problems in vertical U-tube steam generators with Alloy 600 as tube material are localized towards relatively narrow regions above the tube sheet where thermohydraulic conditions and, as a consequence thereof, chemical conditions are uncontrolled. Within these zones Alloy 600 is not sufficienthy resistent to caustic or phosphate attack (caustic stress corrosion cracking and general corrosion, resp.). The mechanisms of several corrosion phenomena are not fully understood. (orig.) [de

  9. Function analysis of steam isolation valves

    International Nuclear Information System (INIS)

    Persson, R.; Kilpi, K.; Noro, H.; Siikonen, T.; Sjoeberg, A.; Wallen, G.; Aakesson, H.

    1981-01-01

    Function analysis of system-medium-operated steam isolation valves has been the objective of the Swedish-Finnish IVLS project, the results of which are presented in this report. Theoretical models were to be verified against available experimental data, to some extent from the HDR blowdown experiments, which are part of a German reactor safety program. Finnish hydraulic measurements on a valve model (scale 1:2.15) have been performed to give complementary data. The analysis work has covered the thermal-hydraulic behaviour of steam isolation valves as well as phenomena related to structural mechanics. Work performed under contract with the Swedish Nuclear Power Inspectorate. (Author)

  10. Function analysis of steam isolation valves

    International Nuclear Information System (INIS)

    Persson, R.; Sjoeberg, A.; Aakesson, H.; Kilpi, K.; Noro, H.; Siikonen, T.; Wallen, G.

    1981-01-01

    Function analysis of system-medium-operated steam isolation valves has been the objective of the Swedish-Finnish IVLS project, the results of which are presented in this report. Theoretical models were to be verified against available experimental data, to some extent from the HDR blowdown experiments, which are part of a German reactor safety program. Finnish hydraulic measurements on a valve model (scale 1:2.15) have been performed to give complementary data. The analysis work has covered the thermal-hydraulic behaviour of steam isolation valves as well as phenomena related to structural mechanics. (Auth.)

  11. Acoustic leak detector in Monju steam generator

    International Nuclear Information System (INIS)

    Wachi, E.; Inoue, T.

    1990-01-01

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

  12. Fourth international seminar on horizontal steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Tuomisto, H [ed.; IVO Group, Vantaa (Finland); Purhonen, H [ed.; VTT, Espoo (Finland); Kouhia, V [ed.; Lappeenranta Univ. of Technology (Finland)

    1998-12-31

    The general objective of the International Seminars of Horizontal Steam Generator Modelling has been the improvement in understanding of realistic thermal hydraulic behaviour of the generators when performing safety analyses for VVER reactors. The main topics presented in the fourth seminar were: thermal hydraulic experiments and analyses, primary collector integrity, feedwater distributor replacement, management of primary-to-secondary leakage accidents and new developments in the VVER safety technology. The number of participants, representing designers and manufacturers of the horizontal steam generators, plant operators, engineering companies, research organizations, universities and regulatory authorities, was 70 from 10 countries.

  13. Fourth international seminar on horizontal steam generators

    International Nuclear Information System (INIS)

    Tuomisto, H.; Purhonen, H.; Kouhia, V.

    1997-01-01

    The general objective of the International Seminars of Horizontal Steam Generator Modelling has been the improvement in understanding of realistic thermal hydraulic behaviour of the generators when performing safety analyses for VVER reactors. The main topics presented in the fourth seminar were: thermal hydraulic experiments and analyses, primary collector integrity, feedwater distributor replacement, management of primary-to-secondary leakage accidents and new developments in the VVER safety technology. The number of participants, representing designers and manufacturers of the horizontal steam generators, plant operators, engineering companies, research organizations, universities and regulatory authorities, was 70 from 10 countries

  14. Stability study in one step steam generators

    International Nuclear Information System (INIS)

    Abbate, P.

    1990-01-01

    The TWO program is presented developed for the behaviour limit calculation stable in one step steam generators for the case of Density Waves phenomenom. The program is based on a nodal model which, using Laplace transformation equations, allows to study the system's transfer functions and foresee the beginning of the unstable behaviour. This program has been satisfactorily validated against channels data uniformly heated in the range from 4.0 to 6.0 Mpa. Results on the CAREM reactor's steam generator analysis are presented. (Author) [es

  15. Steam generator tubesheet waterlancing at Bruce B

    Energy Technology Data Exchange (ETDEWEB)

    Persad, R. [Babcock and Wilcox Canada, Cambridge, Ontario (Canada); Eybergen, D. [Bruce Power, Tiverton, Ontario (Canada)

    2006-07-01

    High pressure water cleaning of steam generator secondary side tubesheet surfaces is an important and effective strategy for reducing or eliminating under-deposit chemical attack of the tubing. At the Bruce B station, reaching the interior of the tube bundle with a high-pressure water lance is particularly challenging due to the requirement to setup on-boiler equipment within the containment bellows. This paper presents how these and other design constraints were solved with new equipment. Also discussed is the application of new high-resolution inter-tube video probe capability to the Bruce B steam generator tubesheets. (author)

  16. Expandable antivibration bar for a steam generator

    International Nuclear Information System (INIS)

    Lagally, H.O.

    1986-01-01

    A steam generator tube support structure comprises expandable antivibration bars positioned between rows of tubes in the steam generator and attached to retaining rings surrounding the bundle of tubes. The antivibration bars have adjacent bar sections with mating surfaces formed as inclined planes which upon relative longitudinal motion between the upper and lower bars provides a means to increase the overall thickness across the structure to the required value. The bar section is retained against longitudinal movement in take-up assembly whereas the bar section is movable longitudinally by rotation of a nut. (author)

  17. Detailed partial load investigation of a thermal energy storage concept for solar thermal power plants with direct steam generation

    Science.gov (United States)

    Seitz, M.; Hübner, S.; Johnson, M.

    2016-05-01

    Direct steam generation enables the implementation of a higher steam temperature for parabolic trough concentrated solar power plants. This leads to much better cycle efficiencies and lower electricity generating costs. For a flexible and more economic operation of such a power plant, it is necessary to develop thermal energy storage systems for the extension of the production time of the power plant. In the case of steam as the heat transfer fluid, it is important to use a storage material that uses latent heat for the storage process. This leads to a minimum of exergy losses during the storage process. In the case of a concentrating solar power plant, superheated steam is needed during the discharging process. This steam cannot be superheated by the latent heat storage system. Therefore, a sensible molten salt storage system is used for this task. In contrast to the state-of-the-art thermal energy storages within the concentrating solar power area of application, a storage system for a direct steam generation plant consists of a latent and a sensible storage part. Thus far, no partial load behaviors of sensible and latent heat storage systems have been analyzed in detail. In this work, an optimized fin structure was developed in order to minimize the costs of the latent heat storage. A complete system simulation of the power plant process, including the solar field, power block and sensible and latent heat energy storage calculates the interaction between the solar field, the power block and the thermal energy storage system.

  18. Study on steam separation in steam generators of a NPP with the WWER-440 reactors

    International Nuclear Information System (INIS)

    Dmitriev, A.I.; Kolzov, Yu.V.; Titov, V.F.; Dubrovin, A.V.; Ilyushin, V.F.; Volkov, A.P.

    1977-01-01

    The separation characteristics as well as the actual level position in steam generators with and without a submerged holy sheet have been determined at a WWER-440 reactor nuclear power plant. It has been shown, that without changing the design of steam generators their load at the WWER-440 reactor nuclear power plant can be increased by about 10%. In this case the vapour humidity does not exceed the permissible value equal to 0.25%. The submerged holy sheet considerably decreases load irregularity and swelling of the water-steam mixture layer

  19. Steam and sodium leak simulation in a fluidized-bed steam generator

    International Nuclear Information System (INIS)

    Vaux, W.G.; Keeton, A.R.; Keairns, D.L.

    1977-01-01

    A fluidized-bed steam generator for the liquid metal fast breeder reactor enhances plant availability and minimizes the probability of a water/sodium reaction. An experimental test program was conceived to assess design criteria and fluidized-bed operation under conditions of water, steam, and sodium leaks. Sodium, steam, and water were leaked into helium-fluidized beds of metal and ceramic particles at 900 F. Test results show the effects of leaks on the heat transfer coefficient, quality of fluidization, leak detection, and cleanup procedures

  20. Economic Analysis of Production of Essential Oil using Steam ...

    African Journals Online (AJOL)

    acer

    Economic Analysis of Production of Essential Oil using. Steam Distillation ... The return on investment (ROI) was 125%, internal rate of return ... oils, over dependency on petrodollar and ... The steam may be obtained from external boiler or.