Radon Cross-Section at Wairakei

Abstract

The radioactive gas radon is produced naturally within the earth's crust by the decay of radium 226. is itself a daughter product of uranium, but constitutes the major source of radioactivity in the lithosphere (Cadi an and Felmlee 1977). thermal situation the would be in radioactive equilibrium with ita parent however experiments in active geothermal areas and hot springs have shown concentrations of radon greatly in excess of radium equilibrium (Grigg and Rogers 1929). by recoil and diffusion into the fluid within the rock and Wood 1972) and may be collected throughout a volume of reservoir by fluid movement. passes but will also lose it again due to radioactive decay. The 3.83 day half life of makes it a useful indicator of fluid movements, and Warren and Kruger (1978) have suggested the measurement of radon on cross-sections of geothermal fields to observe the distribution of steam "age".