Geothermal Injection Monitoring Project. Phase I status report, April 1981-April 1982 (open access)

Geothermal Injection Monitoring Project. Phase I status report, April 1981-April 1982

The feasibility of using remote geophysical techniques to monitor the movement of injected brine has been evaluated. It was established that no single approach is likely to be identified that can be used to accurately monitor the precise location of the injected fluid. Several approaches have been considered in parallel because they add new dimensions to the existing monitoring capabilities, and are likely to cover a range of applications at a variety of geothermal sites. These include: microseismicity - a seismic net is used to record small magnitude events associated with injection; streaming potential - self potential anomalies produced by a moving fluid identify fluid flow direction; cross borehole geotomography - two-dimensional image of flow pathways is constructed using electromagnetic waves; and well pressure response to solid earth tide - changes in pore pressures are used to discriminate fracture/pore porosity and estimate fracture orientations.
Date: August 13, 1982
Creator: Younker, L.; Hanson, J.; Didwall, E.; Kasameyer, P.; Smith, A.; Hearst, J. et al.
Object Type: Report
System: The UNT Digital Library
Laser Fusion Experiments at KMS (open access)

Laser Fusion Experiments at KMS

None
Date: April 13, 1982
Creator: Storm, E. K.
Object Type: Article
System: The UNT Digital Library
Modeling beam-front dynamics at low gas pressures (open access)

Modeling beam-front dynamics at low gas pressures

The dynamics of space charge neutralization at the front of an intense self-focused electron beam pulse exhibits important differences in different gas pressure regimes. At very low pressures, the beam front is in the so-called ion-focused regime (IFR) where all secondary electrons are expelled from the beam region by the radial electric field without causing significant additional ionization. We estimate the upper pressure boundary of this regime by considering the distance scale length for cascade (avalanche) ionization. Data from the FX-25 diode experiments indicate a critical transition pressure (P/sub c/) that agrees with this estimate and with its scaling among various gas types. Normal mobility-limited treatments (local conductivity models) of the secondary electrons at the beam front are not justified until the gas pressure is 10 to 50 times higher than P/sub c/, due to runaway of these secondary electrons in the strong space-charge electric field at the lower pressures. The main conclusion of this study is that a non-local phase space (Boltzmann) treatment of the secondary electrons is required to accurately describe these different beam front regimes and the transitions between them; such a code model is currently under development.
Date: May 13, 1982
Creator: Briggs, R. J. & Yu, S.
Object Type: Report
System: The UNT Digital Library
MPS II drift-chamber system (open access)

MPS II drift-chamber system

A new system of detectors (MPS II) which has been installed and operated in the Brookhaven National Laboratory Multiparticle Spectrometer (MPS), consisting of short drift distance drift chambers is briefly described. (WHK)
Date: May 13, 1982
Creator: Etkin, A.; Eiseman, S. & Foley, K.J.
Object Type: Article
System: The UNT Digital Library
Open grid vs mesh grid as the extraction field structure in a streak camera image-converter tube (open access)

Open grid vs mesh grid as the extraction field structure in a streak camera image-converter tube

It is concluded that the dynamic range of a streak tube does not depend on whether it uses a fine-mesh or an open structure to provide the extraction field. An RCA C-73435 streak tube body was fitted with two extraction grid structures by replacing the conventional open grid with a steel plate containing two apertures. One aperture simulated the open grid structure; the other was a 2 x 20 mm slit covered with a fine mesh (40 wires per mm, 38% transmissive). The apertures were equal distances above and below the tube axis. Using 35-ps pulses, dynamic range curves were taken at 1.06 ..mu..m on one aperture at a time, while blocking the other aperture. As we anticipated, the tube saturated at nearly the same point for the open and mesh apertures. The noise levels for both apertures were almost equal and very close to the film fog level. Noise level was lower than for earlier measurements on other makes of tubes with a fine-mesh grid. The dynamic range for both apertures was in the order of 6000, which indicates that the lower dynamic range of other tubes must be due to something other than the use of a fine-mesh …
Date: May 13, 1982
Creator: Thomas, S. W. & Peterson, R. L.
Object Type: Article
System: The UNT Digital Library
SEBREZ: an inertial-fusion-reactor concept (open access)

SEBREZ: an inertial-fusion-reactor concept

The neutronic aspects of an inertial fusion reactor concept that relies on asymmetrical neutronic effects to enhance the tritium production in the breeding zones have been studied. We find that it is possible to obtain a tritium breeding ratio greater than 1.0 with a chamber configuration in which the breeding zones subtend only a fraction of the total solid angle. This is the origin of the name SEBREZ which stands for SEgregated BREeding Zones. It should be emphasized that this is not a reactor design study; rather this study illustrates certain neutronic effects in the context of a particular reactor concept. An understanding of these effects forms the basis of a design technique which has broader application than just the SEBREZ concept.
Date: January 13, 1982
Creator: Meier, W. R.
Object Type: Article
System: The UNT Digital Library
Technical evaluation report on the proposed design modifications and technical specification changes on grid voltage degradation for the Millstone Nuclear Power Station, Unit 1 (open access)

Technical evaluation report on the proposed design modifications and technical specification changes on grid voltage degradation for the Millstone Nuclear Power Station, Unit 1

This report documents the technical evaluation of the proposed design modifications and Technical Specification change for protection of Class 1E equipment from grid voltage degradation for the Millstone Nuclear Power Station, Unit 1. The review criteria are based on several IEEE standards and the Code of Federal Regulations. The evaluation finds that the licensee has not provided sufficient information on the undervoltage protection system to allow a complete evaluation into the adequacy of protecting the Class 1E equipment from sustained voltage degradation.
Date: May 13, 1982
Creator: Selan, J.C.
Object Type: Report
System: The UNT Digital Library
Underground nuclear explosions at Astrakhan, USSR (open access)

Underground nuclear explosions at Astrakhan, USSR

The three underground nuclear explosions recorded in 1980 and 1981 by Hagfors Observatory in Sweden are in the vicinity of Astrakhan on the Caspian Sea. They are believed to be associated with the development of a gas condensate field discovered in 1973. The gas producing horizons are in limestones at 4000 m depth. They are overlain by bedded, Kungarian salts. Salt domes are recognized in the area. Plans to develop the field are contained in the 11th Five Year Plan (1981-82). The USSR has solicited bids from western contractors to build gas separation and gas processing plant with an annual capacity of 6 billion m/sup 3/. Ultimate expansion plans call for three plants with the total capacity of 18 billion m/sup 3/. By analogy with similar peaceful nuclear explosions described in 1975 by the Soviets at another gas condensate field, the underground cavities are probably designed for storage of unstable, sour condensate after initial separation from the gaseous phases in the field. Assuming that the medium surrounding the explosions is salt, the volume of each cavity is on the order of 50,000 m/sup 3/.
Date: August 13, 1982
Creator: Borg, I.Y.
Object Type: Report
System: The UNT Digital Library