S>Some recent results from the Los Alamos program in which hydraulic fracturing is used for the recovery of geothermal energy are discussed. The location is about 4 kilometers west and south of the ring fault of the enormous Jemez Caldera in the northcentral part of New Mexico. It is shown that geothermal energy may be extracted from hot rock that does not contain circulating hot water or steam and is relatively impermeable. A fluid is pumped at high pressure into an isolated section of a wellbore. If the well is cased the pipe in this pressurized region is perforated as it is in the petroleum industry, so that the pressure may be applied to the rock, cracking it. A second well is drilled a few hundred feet away from the first. Cold water is injected through the first pipe, circulates through the crack, and hot water returns to the surface through the second pipe. Results are described and circumstances are discussed under which artiflcial geothermal reservoirs might be created in the basaltic rock of Hawaii. (MCW)

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The purpose of this test was to demonstrate that the pump utilized for the developmental program to be conducted on the Kilowatt Isotope Power System (KIPS) fulfilled the requirements of Test Procedure 398A, Component Test Procedure for the Ground Demonstration System Pump. The results of the tests are reported. From these results it was concluded that the pump for the Kilowatt Isotope Power System has satisfactorily completed the requirements of Sundstrand Pump Test Procedure, TP 398A.

The resonance capture calculations of the HAMMER System and HAMBUR System are derived from a consistent statement of the integral slowing down equation and definitions of the resonance integral. The assumptions made in these treatments are explicitly stated, and and an attempt is made to estimate the possible error in the resonance integral arising from these assumptions. This analysis is made to pin-point those parts of the calculation that can be improved and updated. Based on the analysis of existing calculations a method of calculation is derived which avoids most of the problems encountered in HAMMER and HAMBUR. The chief improvements that result are as follows: Careful attention is paid to calculation of the resonance flux as most errors in existing calculations result from consistently overpredicting fluxes in all regions of a lattice cell. The calculation can be modified to produce as crude or detailed a resonance calculation, at the expense of computer time, as required by the user. Resonances that overlap group boundaries contribute the correct contribution to each group's reaction rates. Overlap between resonances of different isotopes is correctly accounted for. Up-to-date resonance formalisms are used including the Adler-Adler multi-level formulations. Provision is made to easily add new …

The erosion, corrosion, and stress corrosion cracking (SCC) of Ti-, Co-, Ni-, and Fe-base alloys specimens that were used in scale-control tests performed at the Salton Sea geothermal field were evaluated. Specimens were exposed to high-velocity, two-phase, 104{sup 0}C nozzle exhaust that was produced by expanding acidified hypersaline, highly mineralized brine to atmospheric pressure through converging-diverging nozzles. The exposed specimens were evaluated using surface profilometer traces, light microscopy, scanning-electron microscopy, and energy dispersive spectroscopy ananlysis. The observed degradation was attributed largely to synergistic effects of erosion, corrosion, and stress. A principal mode of degradation appeared to be the formation and growth of corrosion-assisted erosion cavities; it was proposed that surface repassivation kinetics play a key role in the development of these cavities. It was also suggested that scale deposits on the metal surface may either alter the mode of attack or act as protective barriers. It was concluded that, of the potential turbine-blade materials tested, the Ti-base alloys exhibited the best combination of resistance to erosion, corrosion, and SCC.

Four 700-liter cylindrical containers were filled with demineralized water, enriched with nutrients, and inoculated with 3.5-liter lakewater samples. The microcosms were maintained at a temperature of 18/sup 0/C under a 12:12 L:D cycle for 6 months and several manipulations of their trophic structure were carried out, including addition of snails (Physa sp.), mosquitofish (Gambusia affinis), and catfish (Placostomas placostomas). Temporal variation of the phytoplankton resembled the bimodal patterns of certain natural systems. Further analysis demonstrated a close analogy with the predator-prey oscillations of temperate marine waters: an initial bloom is terminated by zooplankton grazing; the resulting low phytoplankton levels lead to gradual starvation of the zooplankton; and a second bloom follows the final dieoff of zooplankton. Both decreasing the concentration of initial nutrients and stocking the microcosms with Gambusia decreases the time between the spring and fall blooms. The problem of heavy periphyton growth in microcosms was not solved with the introduction of either Physa or Placostomas. Possible solutions to this and to other problems peculiar to microcosm research are discussed, and modifications are suggested for increasing the ability of microcosms to simulate natural systems.

Two additional atmospheric sodium release tests were jointly conducted by ESG and ARL at INEL. These tests were conducted under very stable (Pasquill E and G) meteorological conditions where the natural humidity content was high (47 and 96% RH). Sufficient experimental data was obtained on Test 7 to quantitatively qualify the formation of Na/sub 2/CO/sub 3/ in the open atmosphere from primary sodium combustion products. These data show that a maximum concentration of approx. 60% Na/sub 2/CO/sub 3/ is reached with the plume 100 meters from the release point. This concentration increases slightly as the plume is dispersed beyond 2400 meters. The available particle fallout data is consistent with predictions.

The Department of Energy, Minnesota Energy Agency, Northern States Power Company, and other local government and private organizations are cooperatively performing an in-depth application study to determine the feasibility of district heating for a large northern-U.S. city. Over 90% of the space- and water-heating requirements are currently supplied by oil and gas. Hence, district heating can potentially replace large quantities of scarce fuels with coal or nuclear resources. In addition, district heating, using a co-generation power plant, substantially increases the fuel-utilization efficiency when compared to an electric-only plant. A Swedish firm, AB Atomenergi, is performing a preliminary economic and technical assessment. The analysis uses current Swedish district-heating technology and experience, and adapts it, where necessary, to U.S. conditions. Preliminary Swedish results indicate favorable economics for a large system, which includes residential areas, when technology innovations such as temperature-resistant plastic piping are used. For conventional-piping technology the economics appear favorable for the commercial areas of the city core. The peak heat load for the Twin Cities is approximately 4200 MW(t). The scenario presented by AB Atomenergi assumes 2250 MW(t) would be supplied by co-generation units, and the remaining 2000 MW(t) would be peaking, heat-only units. The dual-purpose units would be used …

Lawrence Livermore Laboratory (LLL) is studying ways in which the environmental quality of The Geysers-Calistoga known geothermal resources area may be protected from any significant harmful consequences of future geothermal development. The LLL study includes the effects of development on air and water quality, geology, the ecosystem, socioeconomics, and noise. The Geothermal Resource Impact Projection Study (GRIPS) has grants to undertake similar work. On 28 and 29 November 1977, LLL and GRIPS jointly sponsored a workshop at Sonoma State College at which knowledgeable earth scientists presented their views on the potential geological hazards of geothermal development. The workshop produced recommendations for studies in geological mapping, slope stability, subsidence, seismicity, and groundwater hydrology. These recommendations will be evaluated along with other considerations and in conjunction with the other subjects of the LLL study. The results of the study will be contained in a preplanning report of final recommendations to the Department of Energy.

NIS power range setpoints are given at which the bistable inputs should be set to guarantee compliance with Phase-B Technical Specification Requirements. (JDB)