Analysis of Geothermal Power Plant Water Using Gamma Rays from Capture of Californium-252 Neutrons

The geothermal power effort to extract energy from hot dry rock will require careful water analysis to assist in plant control, to monitor corrosion and solid deposition, and perhaps to recover byproduct minerals. To demonstrate laboratory techniques and indicate plant feasibility, geothermal waters from the Valles Grande Coldera near Jemez Springs, New Mexico were irradiated in laboratory assemblies with neutrons from a ²⁵²Cf source and the high-energy capture gamma rays were measured. The results indicate that chlorine, sodium, calcium, and silicon (and probably other trace elements) can be determined and can help evaluate a geothermal area for power. Such nondestructive analytical techniques applied on-line in the plant, and, depending on neutrons and high-energy gamma rays penetrating thick metal pipes holding the water, should prove useful in the operational needs of the power plant.