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East Mesa geothermal pump test facility (EMPTF). Final report

Description: The design, fabrication and installation of a geothermal pump test facility (EMPFT) at the DOE geothermal site at East Mesa, California which is capable of testing 70 to 750 horsepower downwell pumps in a controlled geothermal environment were completed. The facility consists of a skid-mounted brine control module, a 160 foot below test well section, a hydraulic turbine for power recovery, a gantry-mounted hoist for pump handling and a 3-phase, 480 VAC, 1200 amp power supply to handle pump electric requirements. Geothermal brine is supplied to the EMPTF from one of the facility wells at East Mesa. The EMPTF is designed with a great amount of flexibility. The 20-inch diameter test well can accommodate a wide variety of pumps. The controls are interactive and can be adjusted to obtain a full complement of pump operation data, or set to maintain constant conditions to allow long-term testing with a minimum of operator support. The hydraulic turbine allows the EMPTF user to recover approximately 46% of the input pump power to help defray the operating cost of the unit. The hoist is provided for material handling and pump servicing and reduces the equipment that the user must supply for pump installation, inspection and removal.
Date: November 28, 1984
Creator: Olander, R.G. & Roberts, G.K.
Partner: UNT Libraries Government Documents Department

East Mesa geothermal pump test facility (EMPTF). Final report

Description: Barber-Nichols has completed the design, fabrication and installation of a geothermal pump test facility at the DOE geothermal site at East Mesa, California which is capable of testing 70 to 750 horsepower downwell pumps in a controlled geothermal environment. The facility consists of a skid-mounted brine control module, a 160 foot below ground test well section, a hydraulic turbine for power recovery, a gantry-mounted hoist for pump handling and a 3-phase, 480 VAC, 1200 amp power supply to handle pump electric requirements. Geothermal brine is supplied to the EMPTF from one of the facility wells at East Mesa. The EMPTF is designed with a great amount of flexibility to attract the largest number of potential users. The 20-inch diameter test well can accommodate a wide variety of pumps. The controls are interactive and can be adjusted to obtain a full complement of pump operation data, or set to maintain constant conditions to allow long-term testing with a minimum of operator support. The hydraulic turbine allows the EMPTF user to recover approximately 46% of the input pump power to help defray the operating cost of the unit. The hoist is provided for material handling and pump servicing and reduces the equipment that the user must supply for pump installation, inspection and removal.
Date: November 28, 1984
Creator: Olander, R.G. & Roberts, G.K.
Partner: UNT Libraries Government Documents Department

Np and Pu Sorption to Manganese Oxide Minerals

Description: Manganese oxide minerals are a significant component of the fracture lining mineralogy at Yucca Mountain (Carlos et al., 1993) and within the tuff-confining unit at Yucca Flat (Prothro, 1998), Pahute Mesa (Drellack et al., 1997), and other locations at the Nevada Test Site (NTS). Radionuclide sorption to manganese oxide minerals was not included in recent Lawrence Livermore National Laboratory (LLNL) hydrologic source term (HST) models which attempt to predict the migration behavior of radionuclides away from underground nuclear tests. However, experiments performed for the Yucca Mountain Program suggest that these minerals may control much of the retardation of certain radionuclides, particularly Np and Pu (Triay et al., 1991; Duff et al., 1999). As a result, recent HST model results may significantly overpredict radionuclide transport away from underground nuclear tests. The sorption model used in HST calculations performed at LLNL includes sorption to iron oxide, calcite, zeolite, smectite, and mica minerals (Zavarin and Bruton 2004a; 2004b). For the majority of radiologic source term (RST) radionuclides, we believe that this accounts for the dominant sorption processes controlling transport. However, for the case of Np, sorption is rather weak to all but the iron and manganese oxides (Figure 1). Thus, we can expect to significantly reduce predicted Np transport by accounting for Np sorption to manganese oxides. Similarly, Pu has been shown to be predominantly associated with manganese oxides in Yucca Mountain fractured tuffs (Duff et al., 1999). Recent results on colloid-facilitated Pu transport (Kersting and Reimus, 2003) also suggest that manganese oxide coatings on fracture surfaces may compete with colloids for Pu, thus reducing the effects of colloid-facilitated Pu transport (Figure 1b). The available data suggest that it is important to incorporate Np and Pu sorption to manganese oxides in reactive transport models. However, few data are available for inclusion in our ...
Date: August 30, 2005
Creator: Zhao, P; Johnson, M R; Roberts, S K & Zavarin, M
Partner: UNT Libraries Government Documents Department

Evaluation of Cavity Collapse and Surface Crater Formation for Selected Lawrence Livermore National Laboratory Underground Nuclear Tests - 2007

Description: This report describes evaluation of collapse evolution for selected LLNL underground nuclear tests at the Nevada Test Site (NTS). The work is being done at the request of NSTec and supports the Department of Energy National Nuclear Security Association Nevada Site Office Borehole Management Program (BMP). The primary objective of this program is to close (plug) weapons program legacy boreholes that are deemed no longer useful. Safety decisions must be made before a crater area, or potential crater area, can be reentered for any work. Our statements on cavity collapse and crater formation are input into their safety decisions. The BMP is an on-going program to address hundreds of boreholes at the NTS. Each year NSTec establishes a list of holes to be addressed. They request the assistance of the Lawrence Livermore National Laboratory and Los Alamos National Laboratory Containment Programs to provide information related to the evolution of collapse history and make statements on completeness of collapse as relates to surface crater stability. These statements do not include the effects of erosion that may modify the collapse craters over time. They also do not address possible radiation dangers that may be present. Subject matter experts from the LLNL Containment Program and the Chemical Sciences Division who had been active in weapons testing activities performed these evaluations. Information used included drilling and hole construction, emplacement and stemming, timing and sequence of the selected test and nearby tests, geology, yield, depth of burial, collapse times, surface crater sizes, cavity and crater volume estimations, and ground motion. Both classified and unclassified data were reviewed. Various amounts of information are available for these tests, depending on their age and other associated activities. Lack of data can hamper evaluations and introduce uncertainty. We make no attempt to quantify this uncertainty. The following unclassified summary ...
Date: April 26, 2007
Creator: Roberts, S K; Pawloski, G A & Raschke, K
Partner: UNT Libraries Government Documents Department

Intracrystalline diffusion in clinoptilolite: Implications for radionuclide isolation

Description: Experiments have been performed to measure the rate of exchange diffusion in the zeolite clinoptilolite (CL) for elements important to radionuclide isolation at Yucca Mountain, NV. Clinoptilolite is one of the major sorptive minerals in the tuffs at Yucca Mountain, and occurs both as a major component in zeolitized units (Calico Hills), and in fractures in non-zeolitized tuffs (Topopah Spring). Field evidence and numerical modeling suggests that the movement of fluids through the tuff rocks adjacent to the potential repository may occur via episodic flow through fractures. Under conditions of rapid fracture flow the effective sorptive capacity of fracture-lining clinoptilolite may be controlled by exchange diffusion rather than exchange equilibrium.
Date: November 16, 1995
Creator: Roberts, S.K.; Viani, B.E. & Phinney, D.
Partner: UNT Libraries Government Documents Department

Sodium Reactor Experiment Power Expansion Program: Heat Transfer Systems Modifications

Description: Abstract: Under the Power Expansion Program (PEP), modifications have been made to the Sodium Reactor Experiment (SRE) facility to improve plant reliability and permit an increase in power to 30 Mwt, with a reactor coolant outlet temperature up to 1200°F.
Date: October 9, 1964
Creator: Freede, W. J. & Roberts, J. K.
Partner: UNT Libraries Government Documents Department

Fracture Permeability Evolution in Desert Peak Quartz Monzonite

Description: Fracture flow experiments are being conducted on quartz monzonite core from the Desert Peak East EGS site, Churchill County, Nevada. The flow experiments are conducted at temperatures of 167-169 C and 5.5 MPa confining pressure through artificial fractures. Two injection fluids, a saline solution and a silica-bearing solution, have been used to date. Flow rates are typically 0.02 mL/min, but other rates have been used. The fracture surfaces are characterized with a contact profilometer. The profilometry data demonstrate that it is possible to fabricate statistically similar fracture surfaces and enable us to map aperture variations, which we use in numerical simulations. Effluent samples are collected for chemical analysis. The fluid pressure gradient is measured across the specimen and effective hydraulic apertures are calculated. The experiments show a reduction in permeability over time for both injection fluids, but a more rapid loss of permeability was observed for the silica-bearing solution. The calculated hydraulic aperture is observed to decrease by 17% for the saline solution and 75% for the silica-bearing fluid, respectively. Electrical resistivity measurements, which are sensitive to the ionic content of the pore fluid, provide additional evidence of fluid-rock interactions.
Date: May 10, 2005
Creator: Carlson, S R; Roberts, J J; Detwiler, R L; Viani, B E & Roberts, S K
Partner: UNT Libraries Government Documents Department

California GAMA Special Study: An isotopic and dissolved gas investigation of nitrate source and transport to a public supply well in California's Central Valley

Description: This study investigates nitrate contamination of a deep municipal drinking water production well in Ripon, CA to demonstrate the utility of natural groundwater tracers in constraining the sources and transport of nitrate to deep aquifers in the Central Valley. The goal of the study was to investigate the origin (source) of elevated nitrate and the potential for the deep aquifer to attenuate anthropogenic nitrate. The site is ideal for such an investigation. The production well is screened from 165-325 feet below ground surface and a number of nearby shallow and deep monitoring wells were available for sampling. Furthermore, potential sources of nitrate contamination to the well had been identified, including a fertilizer supply plant located approximately 1000 feet to the east and local almond groves. A variety of natural isotopic and dissolved gas tracers including {sup 3}H-{sup 3}He groundwater age and the isotopic composition of nitrate are applied to identify nitrate sources and to characterize nitrate transport. An advanced method for sampling production wells is employed to help identify contaminant contributions from specific screen intervals. Nitrate transport: Groundwater nitrate at this field site is not being actively denitrified. Groundwater parameters indicate oxic conditions, the dissolved gas data shows no evidence for excess nitrogen as the result of denitrification, and nitrate-N and -O isotope compositions do not display patterns typical of denitrification. Contaminant nitrate source: The ambient nitrate concentration in shallow groundwater at the Ripon site ({approx}12 mg/L as nitrate) is typical of shallow groundwaters affected by recharge from agricultural and urban areas. Nitrate concentrations in Ripon City Well 12 (50-58 mg/L as nitrate) are significantly higher than these ambient concentrations, indicating an additional source of anthropogenic nitrate is affecting groundwater in the capture zone of this municipal drinking water well. This study provides two new pieces of evidence that the ...
Date: April 14, 2010
Creator: Singleton, M J; Moran, J E; Esser, B K; Roberts, S K & Hillegonds, D J
Partner: UNT Libraries Government Documents Department

Mathematical centering on the rigid arm sweep gage

Description: Mathematical Centering, a technique which corrects measurement errors due to part misalignment on the Rigid Arm Sweep Gage, has been in general use at Rocky Flats plant since October 1972. History of the need and development is included. Described also is a theory to explain why some parts appear to be less accurately made when mathematical centering is used than when not used. Capabilities and operator options are discussed and a flow chart given of the basic logic which the computer control program applies. Derivations of formulas have been included in an appendix. (auth)
Date: December 18, 1973
Creator: Seaverson, L. A.; Roberts, O. K.; Burnham, M. W. & De Penning, D. L.
Partner: UNT Libraries Government Documents Department

Safeguards instrumentation for the new Rocky Flats processing facility

Description: This paper describes the safeguards instrumentation planned for the plutonim Waste Processing and Recovery Facility under construction at Rocky Flats Plant. Descriptions are given of the new plutonium Recovery Facility, the material handling systems and the nondesctructive assay equipment.
Date: January 1, 1979
Creator: Haas, F.X.; Gaskins, R.D.; Lawless, J.L.; Minges, G.P. & Roberts, O.K.
Partner: UNT Libraries Government Documents Department

Radionuclide Transport in Tuff and Carbonate Fractures from Yucca Flat, Nevada Test Site

Description: In the Yucca Flat basin of the Nevada Test Site (NTS), 747 shaft and tunnel nuclear detonations were conducted primarily within the tuff confining unit (TCU) or the overlying alluvium. The TCU in the Yucca Flat basin is hypothesized to reduce radionuclide migration to the regional carbonate aquifer (lower carbonate aquifer) due to its wide-spread aerial extent and chemical reactivity. However, shortcuts through the TCU by way of fractures may provide a migration path for radionuclides to the lower carbonate aquifer (LCA). It is, therefore, imperative to understand how radionuclides migrate or are retarded in TCU fractures. Furthermore, understanding the migration behavior of radionuclides once they reach the fractured LCA is important for predicting contaminant transport within the regional aquifer. The work presented in this report includes: (1) information on the radionuclide reactive transport through Yucca Flat TCU fractures (likely to be the primary conduit to the LCA), (2) information on the reactive transport of radionuclides through LCA fractures and (3) data needed to calibrate the fracture flow conceptualization of predictive models. The predictive models are used to define the extent of contamination for the Underground Test Area (UGTA) project. Because of the complex nature of reactive transport in fractures, a stepwise approach to identifying mechanisms controlling radionuclide transport was used. In the first set of TCU experiments, radionuclide transport through simple synthetic parallel-plate fractured tuff cores was examined. In the second, naturally fractured TCU cores were used. For the fractured LCA experiments, both parallel-plate and rough-walled fracture transport experiments were conducted to evaluate how fracture topography affects radionuclide transport. Tuff cores were prepared from archived UE-7az and UE-7ba core obtained from the USGS core library, Mercury, Nevada. Carbonate cores were prepared from archived ER-6-1 core, also obtained from the USGS core library, Mercury, Nevada.
Date: February 1, 2006
Creator: Zavarin, M; Johnson, M R; Roberts, S K; Pletcher, R; Rose, T P; Kersting, A B et al.
Partner: UNT Libraries Government Documents Department