This standard provides a set of typical radionuclide concentrations for estimating the radioactivity in the principal fluid systems of light water reactors and for projecting the expected releases of radioactivity from nuclear plants. It is not intended that the values be used as the sole basis for design but be used in environmental reports and elsewhere where expected operating conditions over the life of the plant would be appropriate. Purpose The purpose of this standard is to provide a uniform approach@ applicable to light water?Ccooled nuclear power plants@ for the determination of expected concentrations in fluid streams. Through application of this standard@ a common basis for the determination of radioactive source terms for normal operating conditions is established@ with the goal of providing a consistent approach for those involved in the design of these facilities. Utilization of this standard is expected to aid the licensing process and the public's understanding of the impact of nuclear power relative to radionuclide concentrations and possible releases to the environment.