Small scale crucible studies were performed by Schumacher to examine the effects of formate and nitrate on glass redox at high copper levels. The results of the crucible studies were used to determine the regions where copper precipitates in the glass. However, durability tests were not performed on the glass samples. Studies were performed in the 774 Research Melter using a simulated feed from the Purex 4 Campaign in the Integrated DWPF Melter System (IDMS). Three runs were performed with this simulated feed. The first used the feed as it was received to determine a baseline. The results from the second and third campaigns were compared to the baseline. The second run increased the copper concentration. The third increased the copper and formate concentrations. The purpose of these experiments was to investigate melter performance and glass durability using a feed with increased copper concentration. The Purex 4 feed did not contain the target amounts of sludge and Precipitate Hydrolysis Aqueous (PHA). Less than 20% of the feed slurry consisted of simulated sludge, making it a low waste-loading feed. The use of this feed with significantly more copper added than anticipated in the DWPF, showed no indication of copper precipitating in …

Numerical experiments are performed to investigate the rock thermal conductivity influence in the formation of the thermodynamic initial conditions of two-phase systems located in volcanic rocks. These systems exhibit pressure and temperature profiles characterized by a sudden change or discontinuity in their vertical gradients. Vapor dominated, two-phase fluids are found at the upper reservoir's levels. Liquid is the dominated phase within the layers below some critical point. Numerical results presented in this paper, suggest that the vertical location of this point of discontinuity be controlled by the thermal conductivity existing between the limit of the reservoir and the caprock. Too high values could originate liquid dominated reservoirs. Small values would be at the origin of vapor dominated reservoirs. A characteristic middle value could be responsible for the formation of a counter flow mechanism originating the initial conditions observed at some locations of the Los Azufres, Mexico, geothermal field.

A detailed three-dimensional numerical model has been developed for the low-temperature hydrothermal system at Botn in Central North Iceland. It is based on a conceptual reservoir model which has evolved during two decades of geothermal research in the area and on the 10 year production history of the system. The model consists of (1) A powerful recharge system at depth, (2) a shallow production reservoir and (3) a cold ground-water system at the surface. About 10 million tons of hot water have been extracted from the production reservoir since late 1981. The presence of the powerful recharge system results in a very slow long-term pressure decline. Flow of water in the production reservoir appears to be controlled by a highly permeable, vertical fracture-zone confined by low-permeability rocks. Cold ground-water flows down into the fracture-zone during production causing some cooling of the extracted water.

A new equation-of-state module has been developed for the TOUGH2 simulator, belonging to the MULKOM family of computer codes developed at LBL. This EOS module is able to handle three-component mixtures of water, sodium chloride, and a non-condensible gas. It can describe liquid and gas phases, and includes precipitation and dissolution of solid salt. The dependence of density, viscosity, enthalpy, and vapor pressure of brine on salt concentration is taken into account, as well as the effects of salinity on gas solubility in the liquid phase and related heat of solution. The main assumptions made in developing this EOS module are discussed, together with the correlations employed to calculate the thermophysical properties of multiphase multicomponent mixtures. At present the non-condensible gas can be chosen to be air, CO₂, CH₄, H₂, or N₂. This paper focuses on H₂O-NaCI-CO₂ mixtures and describes new correlations obtained from fitting of published experimental data. Illustrative results for geothermal reservoir depletion in the presence of salinity and non-condensible gas are presented. We demonstrate and analyze effects of vapor pressure lowering and gas solubility decrease from salinity, and loss of reservoir porosity and permeability from salt precipitation during boiling of brines.

This document provides a discussion of the technical progress on DOE/PETC project number DE-AC22-92PC91338, {open_quotes}High Efficiency SO{sub 2} Removal Testing{close_quotes}, for the time period 1 July through 30 September, 1993. The project involves testing at six full-scale utility flue gas desulfurization (FGD) systems, to evaluate low capital cost upgrades that may allow these systems to achieve up to 98% SO{sub 2} removal efficiency. The upgrades to be evaluated primarily involve the addition of organic acid buffers to the FGD systems. The {open_quotes}base{close_quotes} project involved testing at the Tampa Electric Company Big Bend station. As of September 1993, all five potential options to the base program had been exercised by DOE, involving testing at the Hoosier Energy Merom Station (Option I), the Southwestern Electric Power Company Pirkey Station (Option II), the PSI Energy Gibson Station (Option III), the Duquesne Light Elrama Station (Option IV), and the New York State Electric and Gas Company Kintigh Station (Option V). As of September 1993, testing has been completed for the base project and for Options 1 and 2, has begun but not been completed for Options III and IV, and has not yet begun for Option V. This document is divided into five sections. …

The performance of the 1986 three-dimensional numerical model of the Nesjavellir geothermal field for predicting the deliverabilities and pressure decline of the wells during the period 1987 through 1991 is investigated. The model predicted adequately the flow rate and enthalpy transients of most wells, but overpredicted the pressure decline by 3 to 4 bars.

Through mid-December 1992, long-term flow testing of the Phase I1 Hot Dry Rock (HDR) reservoir at Fenton Hill, NM has been conducted for an aggregate of 24 weeks at near-optimum aseismic injection conditions. This period of flow testing, which began on April 9, 1992, included several reservoir shut-ins due to equipment problems and an intervening lower-injection-rate Interim Flow Test lasting about 6 weeks. With the exceptions noted above, the majority of the flow testing for that period was conducted at an average injection rate of 7.2 l/s and at pressures up to 27.3 MPa. However, this high level of injection pressure has not produced any discernible reservoir microseismicity, indicating that we have been operating the reservoir at pressures below the threshold for fracture extension. The permeation loss from the boundaries of the reservoir at these elevated pressures has averaged about 0.7 l/s, a very low rate of water loss considering the very large volume of fractured rock (about 16x10⁶ m³) comprising the pressure-stimulated reservoir region. Temperature logging across the 350-m production interval, centered at a depth of about 3500 m, indicates that there has been no measurable drop in the mixed-mean reservoir production temperature at the top of this interval …

Estimates of temperatures, past and present, in geothermal reservoirs can be made by using now standard mineralogical techniques, including fluid inclusion geothermometry, vitrinite reflectance, calc-silicate and clay occurrence, the extent of clay interlayering, and measuring clay crystallinity. Recent studies of clays in 60 drillcores from 6 wells at Wairakei, for example, show an inverse relationship between reservoir temperatures and crystallinities from 90&deg; to 225&deg;C (195 to 435°F) (K&uuml;bler Indices: 1.40 to 0.44 <FONT FACE="Symbol">D</FONT>&deg;2<FONT FACE="Symbol">q</FONT>). Fluid inclusion geothermometry results require careful interpretation but the method need not be calibrated with respect to the reservoir, as do other geothermometric methods.

The adiabatic Born-Oppenheimer potential energy surface approximation is not valid for reaction of a wide variety of energetic materials and organic fuels; coupling between electronic states of reacting species plays a key role in determining the selectivity of the chemical reactions induced. This research program initially studies this coupling in (1) selective C-Br bond fission in 1,3- bromoiodopropane, (2) C-S:S-H bond fission branching in CH[sub 3]SH, and (3) competition between bond fission channels and H[sub 2] elimination in CH[sub 3]NH[sub 2].

The adiabatic Born-Oppenheimer potential energy surface approximation is not valid for reaction of a wide variety of energetic materials and organic fuels; coupling between electronic states of reacting species plays a key role in determining the selectivity of the chemical reactions induced. This research program initially studies this coupling in (1) selective C-Br bond fission in 1,3- bromoiodopropane, (2) C-S:S-H bond fission branching in CH{sub 3}SH, and (3) competition between bond fission channels and H{sub 2} elimination in CH{sub 3}NH{sub 2}.

The SRTC has formally transmitted a recommendation to DWPF to replace copper formate with copper nitrate as the catalyst form during precipitate hydrolysis [1]. The SRTC was subsequently requested to formally document the technical bases for the recommendation. A memorandum was issued on August 23, 1993 detailing the activities (and responsible individuals) necessary to address the impact of this change in catalyst form on process compatibility, safety, processibility environmental impact and product glass quality [2]. One of the activities identified was the preparation of a material balance in which copper nitrate is substituted for copper formate and the identification of key comparisons between this material balance and the current Batch 1 sludge -- Late Wash material balance [3].

Using thermodynamic gas equilibria to calculate temperature and steam fraction in the reservoir, three main physical phenomena due to exploitation of Palinpinon field are identified. 1) Pressure drawdown producing a local increase in the computed steam fraction, with the fluid maintaining high temperature values (close to 300°C). Strong decline in flow rate is observed. 2) Irreversible steam losses from the original high temperature liquid phase during its ascent through fractures in upper zones of the reservoir. Steam is generally lost at temperatures (e.g. 240°C) lower then those of the original aquifer. 3) Dilution and cooling effects due to reinjection fluid returns. These are function of the local geostructural conditions linking through fractures the injectors and production wells. The computed fraction of the recovered reinjected brine can in some case exceed 80% of the total produced fluid. At the same time the computed gas equilibration temperatures can decline from 280-300°C to as low as 215-220°C. Comparing these values with the well bottom measured temperatures, the proposed methodology based on gas chemistry gives more reliable temperature estimate than water chemistry based geothermometers for fluids with high fractions of injected brine.

Gas chemistry from 28 wells complement water chemistry and physical data in developing a reservoir model for the Bacon-Manito geothermal project (BMGP), Philippines. Reservoir temperature, T_HSH, and steam fraction, y, are calculated or extrapolated from the grid defined by the Fischer-Tropsch (FT) and H₂-H₂S (HSH) gas equilibria reactions. A correction is made for H₂ that is lost due to preferential partitioning into the vapor phase and the reequilibration of H₂S after steam loss.

Large-scale use of geothermal energy is likely to result in depletion of natural resources that support both biodiversity and other human uses. Most of the problems could be averted with competent planning and adherence to agreed conditions, but they commonly develop because they are not perceived to be directly geothermal in origin and hence are not taken into account adequately. Some of the implications of such issues are discussed below, with particular reference to countries where all or most resources are held under traditional principals of custom ownership.

The occasion of this conference, the Sixth International Conference on Accelerator Mass Spectrometry, falls sixteen years after the remarkable triple simultaneous discovery of this powerful isotopic measurement. In the interval since the Fifth Conference in Paris in 1991, new facilities of both large and small size have become fully operational, achieving impressive gains in both measurement throughput and precision. The purpose of this short review is to extrapolate from recent gains and experience and to project the status of the field beyond the coming millennial date. AMS achieved instant application in archaeology and the geosciences and its early growth was stimulated by the excitement caused by the early results. The ability to obtain an accurate radiocarbon date with a sample one thousand times smaller than possible with scintillation or gas counting, the ability to trace {sup 14}CO{sub 2} in sea water with a similar thousand fold shrinkage in sample size, and the wide utility of {sup 10}Be, {sup 26}Al, {sup 36}Cl, and {sup 129}I as tracers and chronometers of erosion, hydrology and paleoclimate were sufficient to drive the partial conversion of existing accelerators and the construction of new dedicated ones. These applications remain the core of the present field and …

New Energy and Industrial Technology Development Organization (NEDO) did "Geothermal Development Promotion Survey" in the Hachijojima Island which is a volcanic island with 70km&sup2; located in the Izu-Mariana Island Arc. In that national project, NEDO drilled 8 wells in the field and the maximum temperature of the field was 317&deg;C at 1200m depth of a well. Of these survey NEDO confirmed the existence of geothermal reservoir, and using a well named HJ-5, NEDO did short time discharge test. The authors calculated borehole temperature and pressure under production the of the well in comparison with the measured data. The authors also calculated productive performance of another well named HJ-8.

The data from flow tests which employed two different production zones in a well at Fenton Hill indicates the flow impedance of a wellbore zone damaged by rapid depressurization was altered, possibly by pressure spallation, which appears to have mechanically propped the joint apertures of outlet flow paths intersecting the altered wellbore. The rapid depressurization and subsequent flow test data derived from the damaged well has led to the hypothesis that pressure spallation and the resultant mechanical propping of outlet flow paths reduced the outlet flow impedance of the damaged wellbore. Furthermore, transient pressure data shows the largest pressure drop between the injection and production wellheads occurs near the production wellbore, so lowering the outlet impedance by increasing the apertures of outlet flow paths will have the greatest effect on reducing the overall reservoir impedance. Fenton Hill data also reveals that increasing the overall reservoir pressure dilates the apertures of flow paths, which likewise serves to reduce the reservoir impedance. Data suggests that either pressure dilating the wellbore connected joints with high production wellhead pressure, or mechanically propping open the outlet flow paths will increase the near-wellbore permeability. Finally, a new method for calculating and comparing near-wellbore outlet impedances has …

A managed injection program implemented by the NCPA in The Southeast Geysers reservoir continues to positively impact reservoir performance. Injection effects are determined by the application of geochemical and geophysical techniques to track the movement of injectate. This information, when integrated with reservoir pressure, flowrate, and thermodynamic data, is used to quantify the overall performance and efficiency of the injection program. Data analysis indicates that injected water is boiling near the injection wells, without deeper migration, and is recovered as superheated steam from nearby production wells. Injection derived steam (IDS) currently accounts for 25 to 35 percent of total production in the NCPA steamfield. Most importantly, 80 to 100% of the injectate is flashing and being recovered as steam. The amount of IDS has increased since 1988 due to both a change in injection strategy and a drying out of the reservoir. However, significant areas of the reservoir still remain relatively unaffected by injection because of the limited amount of injectate presently available. That the reservoir has been positively impacted in the injection areas is evidenced by a decrease in the rate of pressure decline from 1989 through 1992. Correspondingly, there has been a reduction in the rate of steam …

When liquid is injected into a geothermal reservoir, a fraction of the liquid may vaporise if the reservoir is sufficiently hot. The vapour forms at an approximately planar liquid-vapour interface and diffuses towards the far boundary of the reservoir. If vapour is extracted from the far boundary, then once the new vapour has diffused across the reservoir, the rate of production of vapour at the liquid-vapour interface approximately balances the rate of extraction. We find that if the pressure at the injection pump and extraction well is fixed, then the fraction of the liquid which vaporises and the rate of extraction of vapour from the reservoir increase with time. However, the rate at which liquid is pumped into the reservoir inay initially decrease but subsequently increases with time, if a sufficient fraction of the liquid vaporises. If the mass flux of liquid injected into the reservoir is fixed, then again both the fraction of the liquid which vaporises and the mass flux of vapour which may be extracted increase with time. In this case, the pressure at the injection pump may increase but subsequently decreases with time, again if a sufficient fraction of the liquid vaporises.

An apparatus and method for oxidizing wastes in a two-stage process. The apparatus includes an oxidation device, a gas-liquid contacting column and an electrocell. In the first stage of the process, wastes are heated in the presence of air to partially oxidize the wastes. The heated wastes produce an off-gas stream containing oxidizable materials. In the second stage, the off-gas stream is cooled and flowed through the contacting column, where the off-gas stream is contacted with an aqueous acid stream containing an oxidizing agent having at least two positive valence states. At least a portion of the oxidizable materials are transferred to the acid stream and destroyed by the oxidizing agent. During oxidation, the valence of the oxidizing agent is decreased from its higher state to its lower state. The acid stream is flowed to the electrocell, where an electric current is applied to the stream to restore the oxidizing agent to its higher valence state. The regenerated acid stream is recycled to the contacting column.

This description of work (DOW) details the field activities associated with assessing the vertical extent of groundwater contamination in the uppermost unconfined and confined aquifers beneath the southeastern portion of the 200 West area. The document serves as the test plan for those performing the work. It should be used in conjunction with the Remedial Investigation/Feasibility Study Work Plan for the 200-UP-1 Groundwater Operable Unit, Hanford Site, Richland, Washington (200-UP-1 Operable Unit Workplan) (DOE/RL 1991) for general investigation strategy and with specific procedures. Work scope for the vertical profiling activity is defined in sections 4.2 and 5.1.3 of the 200-UP-1 Operable Unit Workplan. The work is one portion of a proposed Limited Field Investigation (LFI) data collection program.

In experiments at 600°C in the system NaCI-KCI-H₂O, within the analytical uncertainty, stoichiometric quantities of Cl and total alkali metals (Na+K) appear to dissolve in steam coexisting with chloride-rich brine at high pressures in the absence of solid salt. In contrast, at lower pressures, where steam coexists with precipitated salts, significant excess chloride as associated hydrogen chloride (HCI&deg;) dissolves in steam. The HCI&deg; appears to be generated by the reaction of solid NaCl(s) (halite) with steam, producing solid NaOH(s) that diffuses into halite, forming a solid solution. Where HCI&deg; is present highly associated NaOH&deg; as well as associated NaCI&deg; appear to dissolve in steam, and the solubility of each is increased as the mole fraction of NaOH(s) in halite increases. In our quasi-static experiments, compared to dynamic flow-through experiments of others, higher initial ratios of H₂O/NaCI have resulted in higher mole fractions of NaOH(s) in solid solution in halite and, accordingly, higher solubilities of NaCI" and NaOH" dissolved in steam. Addition of quartz to the system NaCI-KCI-H₂O results in the formation of sodium disilicate by reaction of silica with NaOH(s) and an order of magnitude increase in the concentration of HCl&deg; dissolved in steam. In natural hydrothermal systems at lower …

Based on available experimental results and theory, a scenario is presented to achieve ohmic ignition in a spheromak by slow ({approximately} 10 sec.) helicity injection using power from the Mirror Fusion Test Facility (MFTF) substation. Some of the other parts needed (vacuum vessel, coils, power supplies, pumps, shielded building space) might also be obtained from MFTF or other salvage, as well as some components needed for intermediate experiments for additional verification of the concept (especially confinement scaling). The proposed ignition experiment would serve as proof-of-principle for the spheromak DT fusion reactor design published by Hagenson and Krakowski, with a nuclear island cost about ten times less than a tokamak of comparable power. Designs at even higher power density and lower cost might be possible using Christofilos` concept of a liquid lithium blanket. Since all structures would be protected from neutrons by the lithium blanket and the tritium inventory can be reduced by continuous removal from the liquid blanket, environmental and safety characteristics appear to be favorable.

The use of a wellbore simulator, WELLSIM, to characterise the effects of multi-feed inflow on wellbore pressure-temperature characteristics, and diameter changes to a well on the deliverability curve, is discussed. Matching analyses are performed with the simulator on a well which has a number of two-phase and liquid infeeds, and it is demonstrated that good matches to both pressure and temperature profiles can be achieved. The significance of the reservoir/feed response curve for a steam well is illustrated, and the optimisation of wellbore diameter is shown to be related to whether the discharge is wellbore or reservoir controlled.