Summary. Cattle in Reno, Nevada, exhibit a constant very low concentration of I 131 in their thyroid glands in the absence of known releases of I 131 to the atmosphere. This concentration is about 1 picocurie per gram of fresh thyroid tissue. ; This I 131 appears to originate below the tropopause

Summary. In October 1960, increases in the fission product activity of the primary coolant of the SM-1 power plant indicated that a fuel element failure had occurred. Low power tests were run first to determine the nature and magnitude of the defect. Flux tilting experiments were then performed to determine the general location of the failed element. Finally, the primary coolant flowing through each of the fuel elements was sampled at low reactor power for relative iodine activity to determine the exact location of the defective element.. The element was found and replaced. Upon return to power, the fission product activity dropped back to its normal full power value.