Icelandic basaltic geothermal field: A natural analog for nuclear waste isolation in basalt (open access)

Icelandic basaltic geothermal field: A natural analog for nuclear waste isolation in basalt

Analog studies of Icelandic geothermal fields have shown that the design of nuclear waste repositories in basalt can benefit by comparison to the data base already available from the development of these geothermal fields. A high degree of similarity exists between these two systems: their petrology, groundwater geochemistry, mineral solubilities, hydrologic parameters, temperature ranges, water-rock redox equilibria, hydrothermal pH values, and secondary mineralogies all show considerable overlap in the range of values. The experimentally-simulated hydrothermal studies of the basaltic nuclear waste repository rocks have, at this time, produced a data base that receives a strong confirmation from the Icelandic analog. Furthermore, the Icelandic analog should eventually be employed to extrapolate into higher and lower temperatures, into longer time-base chemical comparisons, and into more realistic mineral deposition studies, than have been possible in the laboratory evaluations of the nuclear waste repository designs. This eventual use of the Icelandic analog will require cooperative work with the Icelandic Geological Survey. 46 refs., 4 figs., 2 tabs.
Date: November 21, 1984
Creator: Ulmer, G. C. & Grandstaff, D. E.
System: The UNT Digital Library
Kinetic theory and simulation of multi-species plasmas in tokamaks excited with ICRF microwaves (open access)

Kinetic theory and simulation of multi-species plasmas in tokamaks excited with ICRF microwaves

This paper presents a description of a bounce-averaged Fokker-Planck quasilinear model for the kinetic description of tokamak plasmas. The non-linear collision and quasilinear resonant diffusion operators are represented in a form conducive to numerical solution with specific attention to the treatment of the boundary layer separating trapped and passing orbit regions of velocity space. The numerical techniques employed are detailed in so far as they constitute significant departure from those used in the conventional uniform magnetic field case. Examples are given to illustrate the combined effects of collisional and resonant diffusion.
Date: December 21, 1984
Creator: Kerbel, G. D. & McCoy, M. G.
System: The UNT Digital Library
Dissolving coal at moderate temperatures and pressures. Final report, August 20, 1982-September 30, 1984. [Benzylamine] (open access)

Dissolving coal at moderate temperatures and pressures. Final report, August 20, 1982-September 30, 1984. [Benzylamine]

The main objectives of this research were to make Illinois No. 6 coal liquid or soluble with inexpensive reagents (e.g., solvolysis with methanol and acids), without high pressure equipment, and to see if our soluble products would be more reactive than whole coal in liquefaction processes. These efforts are unpromising. However, efforts to make coal soluble by oxidation with nitric acid gave encouraging results. When Illinois No. 6 and Wyodak coals were allowed to stand in sunlight for 282 days, 27% of the original weight and 32% of the original carbon were lost. Concurrent experiments in the dark at 24/sup 0/C indicate that these coals are fairly stable in air in the dark; light causes most of the oxidation. The solubility properties of these aged coals will not be available before the end of this grant period. Several other minor lines of work, some very interesting, are summarized in order of decreasing significance. 1 figure, 6 tables.
Date: September 21, 1984
Creator: Mayo, F. R.; Hirschon, A. S. & Sundback, K. A.
System: The UNT Digital Library
Geothermal resources assessment in Hawaii. Final report (open access)

Geothermal resources assessment in Hawaii. Final report

The Hawaii Geothermal Resources Assessment Program was initiated in 1978. The preliminary phase of this effort identified 20 Potential Geothermal Resource Areas (PGRA's) using available geological, geochemical and geophysical data. The second phase of the Assessment Program undertook a series of field studies, utilizing a variety of geothermal exploration techniques, in an effort to confirm the presence of thermal anomalies in the identified PGRA's and, if confirmed, to more completely characterize them. A total of 15 PGRA's on four of the five major islands in the Hawaiian chain were subject to at least a preliminary field analysis. The remaining five were not considered to have sufficient resource potential to warrant study under the personnel and budget constraints of the program.
Date: February 21, 1984
Creator: Thomas, D. M.
System: The UNT Digital Library
Octupole anchor for tandem mirrors (open access)

Octupole anchor for tandem mirrors

The octupole anchor is a very promising alternative to the usual quadrupole designs. The most critical unsolved problem is stabilization of the trapped particle mode. The anchor magnetic field is low because MHD stabilization is by hot electrons, thus permitting relatively small magnet currents and conductor cross sections. Increasing the field to a sufficient level to permit operation of the thermal barrier and electrostatic plug required for trapped particle mode stabilization would require much more massive magnets, higher ECRH power, and the much more complex operating scenario associated with standard quadrupole operation. Despite these complications, the absence of a long transition (with an axial minimum in B) between the central cell and the octupole makes the option attractive.
Date: March 21, 1984
Creator: Hopper, E.B. Jr.
System: The UNT Digital Library