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234-5 bank tank circulation studies

Description: In the Plutonium Reclamation Facility a critically-safe geometry of the processing vessels, combined with economical utilization of building space, has resulted in manifolded, vertical tanks for blending, receiving, holding, etc. The pumps attached to the bottom-outlet manifolds of the tanks are of a canned motor type. The extremely short life of these pumps (considerably below that expected even in severe abrasive and corrosive service) prompted a series of studies using glass tanks containing process solutions which, except for the associated radioactivity, duplicate plant process streams. Circulation, blending, and reaction characteristics of simulated process streams in glass duplicates of the 234-5 Bank Tanks TK-17, TK-27, and TK-37 revealed circulation patterns that result in intermittent cavitation within the canned motor transfer pumps. This cavitation, combined with the unavoidable corrosion and abrasion, rapidly destroys the pumps. The circulation patterns, under varying liquid levels as encountered in plant operation, cause single and dual phase transfer of the organic aqueous solutions to process colunans at different times, which results in flooding and erratic extraction efficencies. Reduction of cavitation and elimination of mixed phase transfer has been demonstrated by means of parallel controllable orifices in the external circulation lines. Elimination of cavitation and uniformity of mixing in the four separate vessels comprising the bank-tank assembly have also been demonstrated by means of changes in the inlet and outlet manifolds. The reduction of cavitation can be accomplished by changes in the system components remotely located from the tanks proper, i.e., in piping located in hoods. Complete elimination of cavitation and uniformity requires alteration of the tank headers and, while more desirable, also entails appreciable cost. (auth)
Date: April 30, 1974
Creator: Dunn, J.
Partner: UNT Libraries Government Documents Department

Status of the Magma Energy Project

Description: The current magma energy project is assessing the engineering feasibility of extracting thermal energy directly from crustal magma bodies. The estimated size of the US resource (50,000 to 500,000 quads) suggests a considerable potential impact on future power generation. In a previous seven-year study, we concluded that there are no insurmountable barriers that would invalidate the magma energy concept. Several concepts for drilling, energy extraction, and materials survivability were successfully demonstrated in Kilauea Iki lava lake, Hawaii. The present program is addressing the engineering design problems associated with accessing magma bodies and extracting thermal energy for power generation. The normal stages for development of a geothermal resource are being investigated: exploration, drilling and completions, production, and surface power plant design. Current status of the engineering program and future plans are described. 20 refs., 12 figs.
Date: January 1, 1987
Creator: Dunn, J.C.
Partner: UNT Libraries Government Documents Department

Geothermal technology development at Sandia

Description: Geothermal technology development at Sandia consists of work in two major project areas - Hard Rock Penetration and Magma Energy Extraction. The Hard Rock Penetration Program is directed at reducing drilling costs for geothermal wells. Current activities are focused in three areas: borehole mechanics, rock penetration mechanics, and industry cost-shared research. The Magma Energy Extraction Program is investigating the engineering feasibility of utilizing crustal magma bodies as a source of energy. Work is divided into four major areas: geophysics, geochemistry/materials, drilling, and energy extraction.
Date: April 1, 1987
Creator: Dunn, J.C.
Partner: UNT Libraries Government Documents Department

Energy extraction from crustal magma bodies

Description: An open heat exchanger system for extracting thermal energy directly from shallow crustal magma bodies is described. The concept relies on natural properties of magma to create a permeable, solidified region surrounding a borehole drilled into the magma chamber. The region is fractured, possessing large surface area, and is sealed from the overburden. Energy is extracted by circulating a fluid through the system. Thermal stress analysis shows that such a fractured region can be developed at depths up to 10 km. An open heat exchanger experiment conducted in the partial melt zone of Kilauea Iki lava lake demonstrated the validity of this concept. Effective heat transfer surface area an order of magnitude greater than the borehole area was established during a two-day test period. The open heat exchanger concept greatly extends the number of magma systems that can be economically developed to produce energy.
Date: January 1, 1982
Creator: Dunn, J.C.
Partner: UNT Libraries Government Documents Department

Two-dimensional temperature distribution surrounding an injection well

Description: A two-dimensional analytical solution is obtained for the steady-state temperature distribution in a porous medium during injection of an incompressible fluid. Energy transfer by radial convection and by both radial and axial conduction are included. Temperatures in the porous medium can be expressed in terms of geometry and a nondimensional Peclet number that includes the injection flow rate and properties of the formation and injected fluid. The solution can be applied to the injection of spent brine in geopressured or geothermal systems where temperature distribution near the injection well is needed in order to predict dissolution of suspended solids Radial and axial temperature distributions are presented as a function of the Peclet number.
Date: January 1, 1981
Creator: Dunn, J.C.
Partner: UNT Libraries Government Documents Department

Magma energy

Description: The thermal energy contained in magmatic systems represents a huge potential resource. In the US, useful energy contained in molten and partially-molten magma within the upper 10 km of the crust has been estimated at 5 to 50 x 10/sup 22/ J (50,000 to 500,000 Quads). The objective of the Magma Energy Extraction Program is to determine the engineering feasibility of locating, accessing, and utilizing magma as a viable energy resource. This program follows the DOE/OBES-funded Magma Energy Research Project that concluded scientific feasibility of the magma energy concept. A primary long-range goal of this program is to conduct an energy extraction experiment directly in a molten, crustal magma body. Critical to determining engineering feasibility are several key technology tasks: (1) Geophysics - to obtain detailed definition of potential magma targets, (2) Geochemistry/Materials - to characterize the magma environment and select compatible engineering materials, (3) Drilling - to develop drilling and completion techniques for entry into a magma body, and (4) Energy Extraction - to develop heat extraction technology.
Date: January 1, 1987
Creator: Dunn, J.C.
Partner: UNT Libraries Government Documents Department

Magma energy for power generation

Description: Thermal energy contained in crustal magma bodies represents a large potential resource for the US and magma generated power could become a viable alternative in the future. Engineering feasibility of the magma energy concept is being investigated as part of the Department of Energy's Geothermal Program. This current project follows a seven-year Magma Energy Research Project where scientific feasibility of the concept was concluded.
Date: January 1, 1987
Creator: Dunn, J.C.
Partner: UNT Libraries Government Documents Department

Interaction of ethanol and mercury body burden in the mouse

Description: The interaction of ethanol with mercury in the body resulting in increased exhalation of the metal was studied in the mouse. A persistent elimination of the metal in the breath was demonstrated after single, sublethal (<1 mgHg/Kg body weight) exposures to mercury vapor (Hg/sup 0/) or mercury II chloride (HgCl/sub 2/). The amount of mercury exhaled per unit time was enhanced by oral or parenteral administration of ethanol solutions. These modifications were investigated in dose-response studies in which the drug was administered in doses ranging from 0.2g to 5.5g/Kg to mice pretreated with mercury. The EC/sub 50/ for blood ethanol with respect to mercury exhalation was determined to be approximately 200 mg/dl corresponding to an output rate of approximately 0.1% of the simultaneous body burden in 30 min several days after mercury. A hypothesis that mercury expired by these animals was proportional to the body burden after mercury administration was addressed in experiments whereby mice given one of several doses of mercuric chloride (0.16 to 500 ..mu..g/Kg) were monitored for pulmonary mercury elimination for a fifteen day period. The high correlation obtained between the amount of mercury exhaled in a standard time period and the body burden by group indicated that breath sampling could be applied as an indicator of the mercury body burden which may not be limited to the mouse.
Date: January 1, 1978
Creator: Dunn, J.D.
Partner: UNT Libraries Government Documents Department

Exploration for geothermal resources in the Capital District of New York. Final report

Description: Water chemistry, gas analyses, and geophysical methods including gravity and magnetic surveys, microseismic monitoring, and temperature gradient measurements were used in the Capital District area to evaluate the potential for a hydrothermal geothermal system. Water and gas chemistries provided indirect indicators, and temperature gradients provided direct indications of a geothermal system. Gravity results were supportive of gradient and chemistry data, but seismic and magnetic work have thus far provided little information on the potential system. Gradients throughout the area ranged from an average background value of about 10/sup 0/C/km to a high of roughly 44/sup 0/C/km. The highest gradient values, the most unusual water chemistries and largest carbon dioxide exhalations occur along the Saratoga and McGregor faults between Saratoga Springs and Schenectady, and indicate a good potential for a usable hydrothermal geothermal system at depth.
Date: November 1, 1981
Creator: Sneeringer, M.R. & Dunn, J.R.
Partner: UNT Libraries Government Documents Department

High gain x-ray lasers pumped by transient collisional excitation

Description: We present recent results of x-ray laser amplification of spontaneous emission in Ne-like and Ni-like transient collisional excitation schemes. The plasma formation, ionization and collisional excitation can be optimized using two laser pulses of 1 ns and 1 ps duration at table-top energies of 5 J in each beam. High gain of 35 cm{sup -1} has been measured on the 147 {Angstrom} 4d{r_arrow}4p J=0{r_arrow}1 transition of Ni-like Pd and is a direct consequence of the nonstationary population inversion produced by the high intensity picosecond pulse. We report the dependence of the x-ray laser line intensity on the laser plasma conditions and compare the experimental measurements with hydrodynamic and atomic kinetics simulations for Ne-like and Ni-like lasing.
Date: June 16, 1998
Creator: Dunn, J., LLNL
Partner: UNT Libraries Government Documents Department

Table-top transient collisional excitation x-ray laser research at LLNL: Status June 1997

Description: This is a status report of transient collisional excitation x-ray laser experiments at LLNL during June 1997 that have the advantage of being conducted on a table-top. Two laser drivers with modest energy {approximately}6 J are used in the scheme: a long {approximately}1 ns pulse to preform and ionize the plasma followed by a short {approximately}1 ps pulse to produce the excitation and population inversion. The beams are co-propagated and focused using a combination of a cylindrical lens and paraboloid to a line of {approximately}70 {micro}m x 12.5 mm dimensions. High repetition rates approaching 1 shot/3 min. allow typically in excess of 50 target shots in a day. Various slab targets have been irradiated and we report preliminary results for x-ray laser gain in 3p-3s J=0-1 Ne-like Ti and Fe transitions where gains as high as 24 cm{sup -1} and gL products of {approximately}15 have been observed.
Date: July 1, 1997
Creator: Dunn, J.
Partner: UNT Libraries Government Documents Department

Transient, radial temperature distribution in a porous medium during fluid injection

Description: Analytical and numerical solutions are presented for the transient, radial temperature distribution in a porous medium which is subjected to a constant-rate injection of an incompressible fluid from a wellbore. The formulation includes energy transfer by conduction and convection, and the Danckwerts boundary condition is applied at the finite-radius wellbore. At late times, the numerical solutions approach a self-similar form which can be described in terms of the incomplete Gamma function. In typical petroleum and geothermal applications, convergence to the asymptotic similarity solutions occurs on a time scale of roughly one hour. The results are generally applicable to a broad range of convection-diffusion phenomena which are best described in radial coordinates.
Date: January 1, 1982
Creator: Dunn, J.C. & Nilson, R.H.
Partner: UNT Libraries Government Documents Department

Preliminary considerations for extraction of thermal energy from magma

Description: Simplified mathematical models are developed to describe the extraction of thermal energy from magma based on the concept of a counterflow heat exchanger inserted into the magma body. Analytical solutions are used to investigate influence of the basic variables on electric power production. Calculations confirm that the proper heat exchanger flow path is down the annulus with hot fluid returning to the surface through the central core. The core must be insulated from the annulus to achieve acceptable wellhead temperatures, but this insulation thickness can be quite small. The insulation is effective in maintaining the colder annular flow below expected formation temperatures so that a net heat gain from the formation above a magma body is predicted. The analyses show that optimum flow rates exist that maximize electric power production. These optimum flow rates are functions of the heat transfer coefficients that describe magma energy extraction. 15 refs., 3 figs.
Date: January 1, 1985
Creator: Hickox, C.E. & Dunn, J.C.
Partner: UNT Libraries Government Documents Department

Kilauea Iki lava lake experiment plans

Description: Twelve experimental studies are proposed to complete field laboratory work at Kilauea Iki lava lake. Of these twelve experiments, eleven do not require the presence of melt. Some studies are designed to use proven techniques in order to expand our existing knowledge, while others are designed to test new concepts. Experiments are grouped into three main categories: geophysics, energy extraction, and drilling technology. Each experiment is described in terms of its location, purpose, background, configuration, operation, and feasibility.
Date: January 1, 1981
Creator: Dunn, J.C. & Hills, R.G.
Partner: UNT Libraries Government Documents Department

Overview: Hard Rock Penetration

Description: The Hard Rock Penetration program is developing technology to reduce the costs of drilling and completing geothermal wells. Current projects include: lost circulation control, rock penetration mechanics, instrumentation, and industry/DOE cost shared projects of the Geothermal Drilling organization. Last year, a number of accomplishments were achieved in each of these areas. A new flow meter being developed to accurately measure drilling fluid outflow was tested extensively during Long Valley drilling. Results show that this meter is rugged, reliable, and can provide useful measurements of small differences in fluid inflow and outflow rates. By providing early indications of fluid gain or loss, improved control of blow-out and lost circulation problems during geothermal drilling can be expected. In the area of downhole tools for lost circulation control, the concept of a downhole injector for injecting a two-component, fast-setting cementitious mud was developed. DOE filed a patent application for this concept during FY 91. The design criteria for a high-temperature potassium, uranium, thorium logging tool featuring a downhole data storage computer were established, and a request for proposals was submitted to tool development companies. The fundamental theory of acoustic telemetry in drill strings was significantly advanced through field experimentation and analysis. A new understanding of energy loss mechanisms was developed.
Date: January 1, 1992
Creator: Dunn, J.C.
Partner: UNT Libraries Government Documents Department

Geothermal drilling technology

Description: The report discusses the current state of geothermal drilling technology with reference to how individual technology items are influenced by the following problem areas: high temperature; lost circulation; abrasive rocks; and corrosive gases. (ACR)
Date: January 1, 1986
Creator: Dunn, J.C. & Livesay, B.J.
Partner: UNT Libraries Government Documents Department

Absolute determination of charge-coupled device quantum detection efficiency using Si K-edge x-ray absorption fine structure

Description: We report a method to determine the quantum detection efficiency and the absorbing layers on a front-illuminated charge-coupled device (CCD). The CCD under study, as part of a crystal spectrometer, measures intense continuum x-ray emission from a picosecond laser-produced plasma and spectrally resolves the Si K-edge x-ray absorption fine structure features due to the electrode gate structure of the device. The CCD response across the Si K-edge shows a large discontinuity as well as a number of oscillations that are identified individually and uniquely from Si, SiO{sub 2}, and Si{sub 3}N{sub 4} layers. From the spectral analysis of the structure and K-edge discontinuity, the active layer thickness and the different absorbing layers thickness can be determined precisely. A precise CCD detection model from 0.2-10 keV can be deduced from this highly sensitive technique.
Date: May 6, 2012
Creator: Dunn, J & Steel, A B
Partner: UNT Libraries Government Documents Department

A Model for Large-Scale Thermal Convection in the Long Valley Geothermal Region

Description: A numerical simulation is presented for a simplified model of the Long Valley geothermal system in order to elucidate the nature of the large-scale thermal structure within the system and to assess implications for the drilling program currently underway in the region. The two-dimensional model consists of three horizontal layers, the upper two of which are porous and saturated with a single phase fluid. The system is limited in horizontal extent and heated uniformly from below. An associated planar, natural convective flow is thus produced. The results of the simulation indicate the possibility of wide variations in vertical temperature profiles for the model system, depending on the locations of measurements relative to the convective cells within the layered medium. Thus it can be inferred that, during the early stages of drilling, the vertical temperature distribution may not be a reliable indicator of the presence or absence of the relatively shallow magma body which has been predicted to underlie the geothermal region.
Date: March 24, 1992
Creator: Hickox, C.E. & Dunn, J.C.
Partner: UNT Libraries Government Documents Department

Magma Source Location Survey

Description: A survey of Industry/University geophysicists was conducted to obtain their opinions on the existence of shallow (less than 10 km from surface) magma bodies in the western conterminous United States and methods for locating and defining them. Inputs from 35 individuals were received and are included. Responses were that shallow magma bodies exist and that existing geophysical sensing systems are adequate to locate them.
Date: March 1, 1982
Creator: Hardee, H.C.; Dunn, J.C. & Colp, J.L.
Partner: UNT Libraries Government Documents Department