A report is given of radiographic inspections to estimate the extent of corrosion and scale buildup at the Geothermal Test Site in Calipatria, California. Radiation exposure techniques using 6°Co and 192Ir isotopes were developed. Radiography safety procedures were established. Five radiographic evaluations were made of the Geothermal Test Site from May 1976 to February 1977. Estimations of scale buildup from radiographs of operating plant pipes, valves, and tanks correlated closely with our actual scale measurements from used plant sections.