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Summary Report for Bureau of Fisheries Stream Habitat Surveys : Yakima River Basin, 1934-1942, Final Report. (open access)

Summary Report for Bureau of Fisheries Stream Habitat Surveys : Yakima River Basin, 1934-1942, Final Report.

This document contains summary reports of stream habitat surveys, conducted in the Yakima River basin, by the Bureau of Fisheries (BOF, now National Marine Fisheries Service) from 1934-1942. These surveys were part of a larger project to survey streams in the Columbia River basin that provided, or had provided, spawning and rearing habitat for salmon and steelhead (Rich, 1948). The purpose of the survey was, as described by Rich, 'to determine the present condition of the various tributaries with respect to their availability and usefulness for the migration, breeding, and rearing of migratory fishes'. Current estimates of the loss of anadromous fish habitat in the Columbia River Basin are based on a series of reports published from 1949-1952 by the U.S. Fish and Wildlife Service. The reports were brief, qualitative accounts of over 5000 miles of stream surveys conducted by the BOF from 1934-1946 (Bryant, 1949; Bryant and Parkhurst, 1950; Parkhurst, 1950a-c; Parkhurst et al., 1950). Despite their brevity, these BOF reports have formed the basis for estimating fish habitat losses and conditions in the Columbia River Basin (Fulton, 1968, 1970; Thompson, 1976; NPPC, 1986). Recently, the field notebooks from the BOF surveys were discovered. The data is now archived …
Date: January 1, 1996
Creator: McIntosh, Bruce A.; Clark, Sharon E. & Sedell, James R.
Object Type: Report
System: The UNT Digital Library
Esf Ground Support - Material Dedication Analysis for Structural Steel and Accessories From a Commercial Grade Source (open access)

Esf Ground Support - Material Dedication Analysis for Structural Steel and Accessories From a Commercial Grade Source

The purpose of this analysis is to select the critical characteristics to be verified for steel sets and accessories and the verification methods to be implemented through a material dedication process for the procurement and use of commercial grade structural steel sets and accessories (which have a nuclear safety function) to be used in ground support (with the exception of alcove ground support and alcove opening framing, which are not addressed in this analysis) for the Exploratory Studies Facility (ESF) Topopah Spring (TS) Loop. The ESF TS Loop includes the North Ramp, Main Drift, and South Ramp underground openings.
Date: January 23, 1996
Creator: Stine, M. D.
Object Type: Report
System: The UNT Digital Library
Chemical hydrofracturing of the Hot Dry Rock reservoir (open access)

Chemical hydrofracturing of the Hot Dry Rock reservoir

The experimental study of the water-rock interaction shows that the secondary mineral assemblage depends on the water composition. For example, granite-pure water interaction produces zeolites (relatively low-dense, Mg-poor minerals), whereas seawater yields chlorites (high-dense, Mg-rich minerals). The reactions have volumetric effects from several % to 20 % in magnitude. Volume deformations in the heterogeneous matrix cause uneven mechanical strains. Reactions with the effect of about 0,1 vol.% may cause strains of the order of 100-1000 bars being enough for destruction of rocks. Signs and magnitudes of local volume changes depend on the mineral composition of the secondary assemblage. Hence, one can provide either healing or cracking of primary fractures, as desired, by changing the composition of water in the water-felsic rock system where some elements (Mg, Fe) are in lack. The techniques of "chemical hydrofracturing" looks promising as applied to a granite HDR massif. One can regulate the permeability of fractured flow paths by changing in concord the composition and pressure of the injected water. This approach should promote efficient extraction of the petrothermal energy.
Date: January 24, 1996
Creator: Yakovlev, Leonid
Object Type: Article
System: The UNT Digital Library
Tickling C:AQ5 (open access)

Tickling C:AQ5

The alignment of the quadrupoles in a proton synchrotron is important and the alignment of the low beta quadrupoles in collider mode is even more critical. One of the important considerations is the relationship of the electric center of the Beam Position Monitors (BPMs) to the magnetic center of quadrupoles. Determining this involves measurements when the elements are not in the tunnel and careful alignment utilizing external reference marks when the BPMs are not physically attached to the quadrupole. Even when the BPM is attached to the quadrupole (and calibrated), systematic offsets can be introduced by cable mismatch or slight imbalances in the monitoring electronics. A method has been implemented at Cern [1,2] to determine this relationship using the beam itself. TM-1960 described a proof of principle experiment at the Tevatron using one of the individually powered quadrupoles near the B0 interaction region whose ACNET name is C:AQ7. This short note demonstrates that they can perform the same analysis on a set of quadrupoles powered by a single power supply without having to worry about exciting a single quadrupole.
Date: January 1, 1996
Creator: Moore, Craig D. & Pfeffer, H.
Object Type: Report
System: The UNT Digital Library
BEST: Biochemical Engineering Simulation Technology (open access)

BEST: Biochemical Engineering Simulation Technology

The idea of developing a process simulator that can describe biochemical engineering (a relatively new technology area) was formulated at the National Renewable Energy Laboratory (NREL) during the late 1980s. The initial plan was to build a consortium of industrial and U.S. Department of Energy (DOE) partners to enhance a commercial simulator with biochemical unit operations. DOE supported this effort; however, before the consortium was established, the process simulator industry changed considerably. Work on the first phase of implementing various fermentation reactors into the chemical process simulator, ASPEN/SP-BEST, is complete. This report will focus on those developments. Simulation Sciences, Inc. (SimSci) no longer supports ASPEN/SP, and Aspen Technology, Inc. (AspenTech) has developed an add-on to its ASPEN PLUS (also called BioProcess Simulator [BPS]). This report will also explain the similarities and differences between BEST and BPS. ASPEN, developed by the Massachusetts Institute of Technology for DOE in the late 1970s, is still the state-of-the-art chemical process simulator. It was selected as the only simulator with the potential to be easily expanded into the biochemical area. ASPEN/SP, commercially sold by SimSci, was selected for the BEST work. SimSci completed work on batch, fed-batch, and continuous fermentation reactors in 1993, just as …
Date: January 1, 1996
Creator: unknown
Object Type: Report
System: The UNT Digital Library
D0 Silicon Upgrade: Thermal Conductivity Measurements of a Variety of Epoxies and Greases Used for CDF/D0 Silicon Detector Ladder Construction (open access)

D0 Silicon Upgrade: Thermal Conductivity Measurements of a Variety of Epoxies and Greases Used for CDF/D0 Silicon Detector Ladder Construction

The bulk thermal conductivity of several epoxy mixtures was measured with a setup at Lab D. Samples are prepared by using two aluminum cylinders of 3/4-inch diameter. The cylinders have holes drilled in them for insertion of temperature sensors (0.040-inch diameter thermistors), a heating element (standard resistor), and a tapped hole for heat sinking to a plate. The two cylinders are held together during gluing, and the thickness of the glue bead is controlled by using a shim of kapton tape, nominally 3.5 mils thickness per ply of tape. A resistor is glued into the hole using 5 minute epoxy. Care is taken to avoid shorting the leads to the aluminum cylinder. Once the sample is prepared, the sample is fixed to the heat sink using the tapped hole provided. Thermistors are carefully inserted into the four holes. Once set up, the data acquisition program is run for a half-hour prior to turning on the heater power. This is done to ensure that all temperatures stabilize, and this is checked when doing the analysis. The power is then turned on and run until the temperatures have stabilized, which takes two additional hours. The data acquisition program outputs the four measured …
Date: January 12, 1996
Creator: Gillespie, Gordie; Jostlein, Hans; Ratzmann, Paul & /Fermilab
Object Type: Report
System: The UNT Digital Library
D0 Silicon Upgrade: West End Assembly Hall Platform Design Calculations (open access)

D0 Silicon Upgrade: West End Assembly Hall Platform Design Calculations

This engineering note documents design calculations done for the bayonet feed can platform installed at the far west end of the assembly hall. The platform is mounted off of a cast concrete wall directly south of where the shielding block wall is stacked. A summary of the loading, reaction forces and stresses is shown on the page 3. As can be seen, the calculated stresses are very small, maximum value = 2540 psi. The material used is structural steel tubing, ASTM A500 Gr. B, with a minimum yield strength of 46 ksi and minimum ultimate tensile strength of 58 ksi. The reaction forces for the upper two members will be carried together by a 1/2-inch mounting plate. The mounting plate is attached to the wall by four 1/2-inch Hilti wedge anchors. The allowables for each wedge anchor are 2400 lbs. tensile, 1960 lbs. shear. The major reaction load for the top members is a combined 3627 lbs. tensile load which can easily be handled by the four bolt pattern. Some small moment reactions not listed on the summary page add negligible (400 lbs.) force couples to the axial loading. The bottom members are also attached to a mounting plate that …
Date: January 3, 1996
Creator: Rucinski, Russ
Object Type: Report
System: The UNT Digital Library
12 PWR Assembly MPC Waste Package Criticality Analysis (open access)

12 PWR Assembly MPC Waste Package Criticality Analysis

This analysis was prepared to determine the viability of the MPC PWR-12 waste package concept with respect to criticality regulatory requirements in compliance with the goals of the Waste Package Implementation Plans for conceptual design.
Date: January 18, 1996
Creator: Davis, J.
Object Type: Report
System: The UNT Digital Library
MATERIAL COMPOSITIONS AND NUMBER DENSITIES FOR NEUTRONICS CALCULATIONS (open access)

MATERIAL COMPOSITIONS AND NUMBER DENSITIES FOR NEUTRONICS CALCULATIONS

The purpose of this analysis is to calculate the number densities and isotopic weight percentages of the standard materials to be used in the neutronics (criticality and radiation shielding) evaluations by the Waste Package Development Department. The objective of this analysis is to provide material number density information which can be referenced by future neutronics design analyses, such as for those supporting the Conceptual Design Report.
Date: January 2, 1996
Creator: Thomas, D. A.
Object Type: Report
System: The UNT Digital Library
Stimulation of well SN-12 in the Seltjarnarnes low-temperature field in SW-Iceland (open access)

Stimulation of well SN-12 in the Seltjarnarnes low-temperature field in SW-Iceland

Well SN-12 in the Seltjarnarnes low-temperature field in SW-Iceland was drilled to a depth of 2714 m in the fall of 1994. The well appeared to be almost non-productive at the end of drilling. A comprehensive ten day stimulation program was, therefore, initiated. The program involved, firstly, high-pressure wellhead injection and, secondly, high-pressure injection below a packer placed at 1412 m depth. After about twelve hours of wellhead stimulation the pressure dropped suddenly, indicating that the well had been stimulated. At the same time the water level response increased suddenly in two near-by monitoring wells. During the second stimulation phase (packer at 1412 m) the well appeared to be stimulated even further. The well eventually produced about 35 l/s with a drawdown of roughly 60 m, and the stimulation had increased the yield of the well by a factor of nearly 60. Thus well SN-12, which appeared to be almost non-productive at the completion of drilling, had turned into a good production well. It is believed that during the stimulation some previously closed fractures, or interbed contacts, reopened connecting well SN-12 to the main fracture system of the geothermal reservoir.
Date: January 24, 1996
Creator: Tulinius, Helga; Axelsson, Gudni; Tomasson, Jens; Kristmannsdottir, Hrefna & Gudmundsson, Asgrimur
Object Type: Article
System: The UNT Digital Library
NORTH PORTAL - HOT WATER CIRCULATION PUMP CALCULATION - SHOP BUILDING #5006 (open access)

NORTH PORTAL - HOT WATER CIRCULATION PUMP CALCULATION - SHOP BUILDING #5006

None
Date: January 25, 1996
Creator: Blackstone, R.
Object Type: Report
System: The UNT Digital Library
Natural analogs for enhanced heat recovery from geothermal systems (open access)

Natural analogs for enhanced heat recovery from geothermal systems

High-temperature hydrothermal systems are physically and chemically zoned with depth. The energy input is from a magmatic zone, intruded by igneous bodies, that may also contribute variable amounts of magmatic fluid to the system. The heat source is directly overlain by a section of rocks, that due to their elevated temperature, respond to stress in a ductile fashion. The ductile zone is, in turn, overlain by a section of rocks that respond to stress in a brittle fashion, where water is able to circulate through fractures (the geothermal reservoir) and will be termed the hydrothermal circulation zone. Ancient and modern high-temperature geothermal systems show a predictable sequence of evolutionary events affecting these stratified zones. Metamorphic core complexes are uplifts, formed in highly extended terrains, that expose fossil brittle-ductile transition zones. Formerly ductile rocks have had brittle fractures superimposed on them, and meteoric hydrothermal systems are associated with the brittle fracturing. Porphyry copper deposits typically evolve from magmatic to meteoric hydrothermal systems. At the Larderello geothermal system, the brittle- ductile transition has been mapped using reflection seismology, and the zone has been penetrated by the San Pompeo 2 well where temperatures >420°C were encountered. Although neo-granitic dikes have been penetrated by …
Date: January 24, 1996
Creator: Nielson, Dennis L.
Object Type: Article
System: The UNT Digital Library
Simulation studies for wells AH-4bis/AH-17 and AH-18, Ahuachapan Geothermal Field (open access)

Simulation studies for wells AH-4bis/AH-17 and AH-18, Ahuachapan Geothermal Field

Well AH-4<sub>bis</sub>, at the Ahuachapan Geothermal Field is planned to be drilled on the same pad as the former AH-4. A simulation study was carried out for two casing dameters 13 5/8 and 9 5/8” in order to estimate its production and to know its economic feasibility. The simulation results indcate a high probability of production in the range of 7 Mwe, equivalent to 120 kg/s total mass flow rate, 1250 kJ/kg at 6 bar-a for the new well AH-4<sub>bis</sub>. Well AH- 17 is good producer, during 1991 after ten years of production, the well was shut-in due to silica scaling problems. A wellbore simulation was carried out in order to predict the new production conditions after the work-over, mainly to estimate the water flow rate in order to reduce the silica scaling. The results indicate a very low water flow rate. The match between the simulated and measured production curves after the work-over was successful. The well AH-18 is located at the southern part of the actual bore field. CEL is planning to expand the borefield at this area and it is neccessary to estimate the possible production condtions at that zone. The results indicate a high probabilty of …
Date: January 24, 1996
Creator: Monterrosa, Manuel Ernesto
Object Type: Article
System: The UNT Digital Library
Permeability, electrical impedance, and acoustic velocities on reservoir rocks from the Geysers geothermal field (open access)

Permeability, electrical impedance, and acoustic velocities on reservoir rocks from the Geysers geothermal field

Previous measurements of acoustic velocities on NEGU- 17 cores indicate that saturation effects are significant enough to cause V<sub>p</sub>/V<sub>s</sub> anomalies observed in the field. In this study we report on the results of new measurements on core recently recovered from SB-15-D along with some additional measurements on the NEGU-17 cores. The measurements indicate correlations between mechanical, transport, and water storage properties of the matrix which may prove useful for reservoir assessment and management. The SB-15-D material is found to be similar to the NEGU-17 material in terms of acoustic velocities, being characterized by a notably weak pressure dependence on the velocities and a modest V<sub>p</sub>/V<sub>s</sub> signature of saturation. The effect of saturation on V<sub>p</sub>/V<sub>s</sub> appears to result in part from a chemo-mechanical weakening of the shear modulus due to the presence of water. Electrical properties of SB-15-D material are qualitatively similar to those of the NEGU-17 cores, although resistivities of SB-15-D cores are notably lower and dielectric permittivities higher than in their NEGU- 17 counterparts. While some limited correlations of measured properties with depth are noted, no clear change in character is observed within SB-15-D cores which can be associated with the proposed cap-rock/reservoir boundary.
Date: January 24, 1996
Creator: Boitnott, G.N. & Boyd, P.J.
Object Type: Article
System: The UNT Digital Library
Tough2/PC application simulation project for Heber geothermal field, California, a progress report (open access)

Tough2/PC application simulation project for Heber geothermal field, California, a progress report

A numerical simulation model for the Heber geothermal field in Southern California is being developed under a technology transfer agreement between the Department of Energy/Lawrence Berkeley National Laboratory (LBNL) and the California Department of Conservation, Division of Oil, Gas, and Geothermal Resources (DOGGR). The main objectives of the cooperation are (1) to train DOGGR personnel in the use of the TOUGH2PC computer code; and (2) to develop a module compatible with TOUGH2 to investigate the effects of production/injection operations on the ground surface subsidence-rebound phenomenon observed in the Heber geothermal field. Initial-state calibration (undisturbed system) runs are being conducted to calibrate the model.
Date: January 24, 1996
Creator: Boardman, Timothy S.; Khan, M. Ali & Antunez, Emilio
Object Type: Article
System: The UNT Digital Library
Interpretation of interference effects in three production wells in the Kawerau geothermal field, New Zealand (open access)

Interpretation of interference effects in three production wells in the Kawerau geothermal field, New Zealand

Downhole temperature and pressure, mass flow, and enthalpy measurements on three production wells at Kawerau geothermal field are interpretted to illustrate interference effects between these wells. Feed zone locations within the wells, together with geology and chemistry are discussed. Downhole measurements are made in one well while production flow changes are made on another well to monitor pressure transient effects. The interference effects have implications for planning future production drilling.
Date: January 24, 1996
Creator: Stevens, Lynell & Koorey, Kevin J.
Object Type: Article
System: The UNT Digital Library
CT imaging of two phase flow in fractured porous media (open access)

CT imaging of two phase flow in fractured porous media

This paper describes the design, construction, and preliminary results of an experiment that studies imbibition displacement in two fracture blocks. Three core configurations were constructed. The configurations are a compact core, a two-block system with a 1 mm spacer between the blocks, and a two-block system with no spacer. The blocks are sealed in epoxy so that saturation measurements can be made throughout the displacement experiments using a Computed Tomography (CT) scanner. Preliminary results are presented from a water/air experiment. These results suggest that it is incorrect to assume negligible capillary continuity between matrix blocks as is often done.
Date: January 24, 1996
Creator: Hughes, Richard G.; Brigham, William E. & Castanier, Louis M.
Object Type: Article
System: The UNT Digital Library
Fracture permeability in the Matalibong-25 corehole, Tiwi geothermal field, Philippines (open access)

Fracture permeability in the Matalibong-25 corehole, Tiwi geothermal field, Philippines

The Tiwi geothermal field is located in southern Luzon on the northeast flank of Mt. Malinao, an andesitic volcano that was active 0.5 to 0.06 Ma. Matalibong-25 (Mat-25) was drilled through the Tiwi reservoir to investigate lithologic and fracture controls on reservoir permeability and to monitor reservoir pressure. Continuous core was collected from 2586.5 to 8000 feet (789 to 2439 meters) with greater than 95% recovery. The reservoir rocks observed in Mat-25 consist mainly of andesitic and basaltic lavas and volcaniclastic rocks above 6600 feet depth (2012 meters) and andesitic sediments below, with a transition from subaerial to subaqueous (marine) deposition at 5250 feet (1601 meters). The rocks in the reservoir interval are strongly altered and veined. Common secondary minerals include chlorite, illite, quartz, calcite, pyrite, epidote, anhydrite, adularia and wairakite. An <sup>39</sup>Ar/<sup>40</sup>Ar age obtained on adularia from a quartz-adularia-cemented breccia at a depth of 6066 feet (2012 meters) indicates that the hydrothermal system has been active for at least 320,000 years. Fractures observed in the core were classified as either veins (sealed) or open fractures, with the latter assumed to represent fluid entries in the geothermal system. Since the core was not oriented, only fracture frequency and dip angle …
Date: January 24, 1996
Creator: Nielson, Dennis L.; Clemente, Wilson C.; Moore, Joseph N. & Powell, Thomas S.
Object Type: Article
System: The UNT Digital Library
Reservoir investigations on the Hot Dry Rock geothermal system, Fenton Hill, New Mexico: Tracer test results (open access)

Reservoir investigations on the Hot Dry Rock geothermal system, Fenton Hill, New Mexico: Tracer test results

A closed-loop circulation test was conducted from 10 May to 14 July 1995 on the Hot Dry Rock (HDR) reservoir at Fenton Hill, New Mexico after a hiatus of nearly two years. Changes in heat transfer and reservoir volume were investigated and compared to previous circulation tests. Chemical tracers can be used to measure the volume of flow paths in hydrologic systems. Usually, tracers are used in low temperature situations, but the application to high temperature systems has been established for certain tracer compounds. During the 1995 flow testing at Fenton Hill, both a conservative and a non conservative tracer were injected into the reservoir in each of two separate experiments. The purpose was to determine the volume of the most direct flow paths and to estimate the total volume of fractures in the system. The results indicate a relatively static reservoir volume between June and July, yet with an increase in flow dispersion. It can be assumed that channeling of flow did not occur in the main body of the reservoir due to continuous operation. However, a new flow path adjacent to the injection well did develop, and its affect on reservoir flow was investigated using tracer technology. The …
Date: January 24, 1996
Creator: Callahan, Timothy J.
Object Type: Article
System: The UNT Digital Library
Permeability decrease in argillaceous sandstone; experiments and modelling (open access)

Permeability decrease in argillaceous sandstone; experiments and modelling

Core flooding experiments on argillaceous sandstone are carried out showing that for high injection flow rates permeability reduction occurs. The decrease of permeability is a consequence of the migration of insitu particles. Two models are used to simulate the observed phenomena. The so-called network model is able to give insight in the physics behind the particle migration. The other model based on mass balance and constitutive laws is used for quantitative and qualitative comparison with the experiments.
Date: January 24, 1996
Creator: Egberts, Paul; van Soest, Lennard & Vernoux, Jean-Francois
Object Type: Article
System: The UNT Digital Library
A study of relative permeability for steam-water flow in porous media (open access)

A study of relative permeability for steam-water flow in porous media

We report on continuing experimental and numerical efforts to obtain steam-water relative permeability functions and to assess effect of heat transfer and phase change. To achieve these, two sets of steady-state flow experiments were conducted: one with nitrogen and water and another with steam and water. During these experiments, a mixture of nitrogen-water (or steam-water) was injected into a Berea sandstone core. At the onset of steady state conditions, three-dimensional saturation distributions were obtained by using a high resolution X-ray computer tomography scanner. By identifying a length of the core over which a flat saturation profile exists and measuring the pressure gradient associated with this length, we calculated relative permeabilities for nitrogen-water flow experiments. The relative permeability relations obtained in this case were in good agreement with those reported by other investigators. Another attempt was also made to conduct a steam-water flow experiment under adiabatic conditions. This experiment was completed with partial success due to the difficulties encountered during the experiment. The results of this experiment showed that a flat saturation profile actually developed over a substantial length of the core even at a comparatively modest injection rate (6 grams per minute) with low steam quality (4% by mass). The …
Date: January 24, 1996
Creator: Ambusso, Willis; Satik, Cengiz & Horne, Roland
Object Type: Article
System: The UNT Digital Library
A study of electrical generating capacities of self-discharging slim holes (open access)

A study of electrical generating capacities of self-discharging slim holes

Theoretical calculations have been performed to estimate the electrical generating capacities of small-diameter geothermal wells for off-grid rural electrification using wellhead generators. In these applications, generating capacities of interest are typically in the range 100-1000 kWe. The approach amounted to (1) calculating the “wellhead discharge characteristics” (water/steam discharge rates as functions of wellhead pressure) for a variety of hypothetical well and reservoir descriptions, (2) employing a mathematical representation for the net generating capacity of a wellhead powerplant as a function of its operating inlet pressure and steam inlet rate, and (3) varying the wellhead (= turbine inlet) pressure to identify the “optimum” pressure value at which the net electrical power is maximized. Calculations were carried out for well diameters from 75 mm to 300 mm, for well depths from 300 to 1200 meters, for reservoir temperatures from 100°C to 240&deg;C, for piezometric surface depths (related to shut-in reservoir pressure) from zero to 250 meters, and for downhole productivity indices from 2 kg/s/bar to infinity. A few cases were also included in which the CO<sub>2</sub> content of the reservoir fluid was non-zero (up to 1% by mass in the brine). Both backpressure and condensing single-flash steam turbine powerplants were considered. The …
Date: January 24, 1996
Creator: Pritchett, J. W.
Object Type: Article
System: The UNT Digital Library
Environmental impact of landfill disposal of selected geothermal residues (open access)

Environmental impact of landfill disposal of selected geothermal residues

A solid waste is classified as hazardous if it contains sufficient leachable components to contaminate the groundwater and the environment if disposed in a landfill. Scale, sludge and drilling mud from three geothermal fields (Bulalo, Phlippines; Cerro Prieto, Mexico; and Dixie Valley, USA) containing regulated elements at levels above the earth‘s crustal abundance were studied for their leachability. Cr, As, Cu, Zn and Pb were detected at levels which could impair groundwater quality if leaching occurred. Several procedures were used to assess the likely risk posed by the residues : protocol leaching tests (Canadian LEP and US TCLP), toxicity testing, accelerated weathering test, and a preliminary acid mine drainage potential test. Whole rock analysis, X-ray diffraction, and radioactivity counting were also performed to characterize the samples. Toxi-chromotest and SOS-chromotest results were negative for all samples. Leachng tests indicated that all of them could be classified as nonhazardous wastes. Only one of the six showed a low-level radioactivity based on its high Pb-210 activity. Initial tests for acidification potential gave positive results for three out of six samples whle none of the regulated elements were found in the leachate after accelerated weathering experiment for three months.
Date: January 24, 1996
Creator: Peralta, G.L.; Graydon, J.W.; Seyfried, P.L. & Kirk, D.W.
Object Type: Article
System: The UNT Digital Library
Experimental verification of the load-following potential of a Hot Dry Rock geothermal reservoir (open access)

Experimental verification of the load-following potential of a Hot Dry Rock geothermal reservoir

A recent 6-day flow experiment conducted at the Los Alamos National Laboratory's Fenton Hill Hot Dry Rock (HDR) test site in north-central New Mexico has verified that an HDR reservoir has the capability for a significant, and very rapid, increase in power output upon demand. The objective of this cyclic load-following experiment was to investigate the performance of the reservoir in a nominal high-backpressure (2200 psi) baseload operating condition upon which was superimposed greatly increased power production for a 4-hour period each day. In practice, this enhanced production was accomplished by dropping the production well backpressure from the preexisting level of 2200 psi down to about 500 psi to rapidly drain the fluid stored in the pressure-dilated joints surrounding the production well. During the last cycle of this six-cycle test, the mean production conditions were 146.6 gpm for 4 hours at a temperature of 189°C followed by 92.4 gpm for 20 hours at a temperature of 183°C. These flow and temperature values indicate a flow enhancement of 59%, and a power enhancement of 65% during the high-production period. The time required to increase the reservoir power output from the baseload to the peaking rate was about 2 minutes.
Date: January 24, 1996
Creator: Brown, Donald
Object Type: Article
System: The UNT Digital Library