The technology development activities of the Geothermal Energy Program at the Lawrence Livermore Laboratory are summarized. Significant progress toward development of the Total-Flow concept was made during FY 1978. The results show that the original goal of 70% engine efficiency for the Total-Flow impulse turbine is achievable, that a Total-Flow system is competitive economically with conventional systems, and that the Total-Flow concept offers the benefit of more efficient utilization of geothermal resources for electric power production. The evaluation of several liquid expanders designed for low-temperature (including geopressured) resources suggests that if development were continued, these expanders could be used in combination with conventional systems to increase overall system efficiency. Although the program was terminated before complete field testing of prototype systems could be carried out, the concepts have been adopted in other countries (Japan and Mexico), where development is continuing.

Eight prototype solar heating and combined heating and cooling systems are under development. This effort includes development, manufacture, test, installation, maintenance, problem resolution, and performance evaluation.

Pilot studies have been completed using 275-..mu..m bone char as an adsorbent for the removal of plutonium, in concentrations ranging up to 8 mg/liter, from caustic waste solutions. These waste solutions were adjusted to an approximate pH of 8 before they were passed through columns of the bone char. Overall decontamination factors of about 5 x 10/sup 9/ were obtained. A tentative design of a caustic waste treatment system utilizing cartridge filters and bone char columns was made. Its advantages and possible cost saving benefits are assessed.