This report was prepared as an account of work sponsored by an agency of the United States Government.

LASNEX calculations for focused laser beams on spherical targets have been performed for laser wavelengths of 0.25, 0.5, 1.0 and 2.0 microns. One-dimensional calculations, including the ponderomotive force, show a profile steepening that determines the fractional absorption by anomalous mechanism. However, increased absorption occurs at the shorter wavelengths because of more efficient inverse bremsstrahlung absorption at the higher critical densities. In general, the absorption efficiency increases with shorter laser wavelength and decreases with increasing f-number of the illuminating optics for sufficiently long plasma scale lengths. The effect of the absorption and laser wavelength on the thermal and superthermal electron physics will be discussed along with the combined effects on the implosion performance. Certain aspects of two-dimensional LASNEX calculations are presented.

A two-year baseline water quality study was conducted in the Imperial Valley. The data accumulated, together with the drinking and irrigation water criteria and the known costs of chemical analyses, augment findings on brine chemistry throughout the Valley and on constituents in the Vail 4A Drain, an agricultural drain in the Salton Sea KGRA. These suggest minimum parameters that should be monitored in future programs for water quality management during the development of the geothermal resources in Imperial Valley. They are concentrations of B, Li, Mn, Zn, Na, K, Ca, Mg, Cl, SO{sub 4}, CO{sub 3}, and HCO{sub 3}, TDS, SC, pH, and temperature. Arsenic, Se, Pb, and Ni should also be considered in the future because of their possible elevation in some brines above existing water quality criteria. (JGB)

The General Atomic codes TAP (Transient Analysis Program) and RECA (Reactor Emergency Cooling Analysis) are evaluated with respect to their capability for predicting the dynamic behavior of high-temperature gas-cooled reactors (HTGRs) for postulated accident conditions. Several apparent modeling problems are noted, and the susceptibility of the codes to misuse and input errors is discussed. A critique of code verification plans is also included. The several cases where direct comparisons could be made between TAP/RECA calculations and those based on other independently developed codes indicated generally good agreement, thus contributing to the credibility of the codes.

Results of work done on potential geologic effects of geothermal development are discussed. The key geological issues in the Imperial Valley are the potential for significant subsidence and seismicity which could be induced by geothermal production. The major technical problem is to develop techniques to distinguish between natural and induced activity. In both subsidence and seismicity studies, the projects augment the existing network to obtain additional information in critical areas; thus, local subsidence detection networks were added to the regional networks. The U.S. Geological Survey seismograph network was augmented to increase sensitivity to small earthquakes near the Salton Sea. Techniques being used and initial results are summarized briefly. (JGB)

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, John L. Hill, regarding a legal question submitted for clarification: Whether employees of the School Tax Assessment Practices Board are members of the Teacher Retirement System of Texas or the Employees Retirement System of Texas.

A weekly publication, the Texas Register serves as the journal of state agency rulemaking for Texas. Information published in the Texas Register includes proposed, adopted, withdrawn and emergency rule actions, notices of state agency review of agency rules, governor's appointments, attorney general opinions, and miscellaneous documents such as requests for proposals. After adoption, these rulemaking actions are codified into the Texas Administrative Code.