A theoretical expression showing the radial dependence of permeability in geologic media as a function of the distance from the point of detonation has been derived. This relationship shows that created permeability decreases as a function of radius (1/r/sup 5/ around a spherical blast and 1/r/sup 4/ around a cylindrical shot). Excellent correlation was found when this prediction was compared with permeability measurements made around the site of the Hardhat nuclear event fired in granodiorite and a chemical explosive detonated in coal. (auth)

A procedure, called the threshold cross section method was applied to our experimental data involving four uranium (/sup 233/U /sup 234/U, /sup 236/U, and /sup 238/U) and five plutonium (/sup 239/Pu, /sup 240/Pu, /sup 241/Pu, /sup 242/Pu, and /sup 244/Pu) isotopes to determine ratios of fission cross sections relative to /sup 235/U. The data were gathered using ionization fission chambers and the time-of-flight technique at the LLL 100-MeV electron linear accelerator: measurements span the neutron energy range of 0.001 to 30 MeV. Experimental uncertainties common to past measurements were either eliminated or significantly reduced in this study by use of the threshold method, thereby making higher accuracies possible. The cross section ratios are absolute in the sense that they do not depend on the work of others. Results from our ratios involving /sup 233/U, /sup 235/U, /sup 238/U, and /sup 239/Pu are used to illustrate this method.

An x-ray gauging method was developed and a production gauging system was subsequently fabricated to control the quality of precision manufactured components. The gauging system measures via x-ray absorption the density of pressed finely divided solids held in a dissimilar container. The two dissimilar materials condition necessitated a ''two scan'' technique: first, the x-ray attenuation (absorption) of the empty container prior to loading and then, the attenuation of the loaded container are measured; that is, four variables. The system provided greatly improved product control via timely data feedback and increased product quality assurance via 100 percent inspection of product. In addition, it reduced labor costs, product cost, and possibilities for human errors.

The Lawrence Livermore Laboratory has been appointed by the U.S. Energy Research and Development Administration to be the lead laboratory for carrying out a long-term project to acquire complete understanding of the environmental quality in the Imperial Valley of California prior to any major developments. The purpose of this project is to ensure that the development of geothermal resources proceeds on an environmentally sound basis. Consequently, the Imperial Valley Environmental Project (IVP) is committed to an intensive and comprehensive study designed to establish an environmental baseline for the Imperial Valley as well as to develop an understanding of the environmental and other effects associated with development of geothermal resources. The IVP is organized into seven main study sections, which when taken together cover all the significant issues and concerns. The sections are: Air Quality; Water Quality; Ecosystem Quality (Soil, Plants, Animals, etc.); Subsidence and Induced Seismicity; Health Effects; Socio-Economics; and an Integrated Assessment. (auth)