ANS Publishes Revised Radioactive Source Term Standard

ANSI/ANS-18.1-2016, “Radioactive Source Term for Normal Operation of Light Water Reactors,” (revision of historical standard ANSI/ANS-18.1-1999) has just been published. This standard updates the default activity concentrations and adjustment factors based on the latest review of data from operating domestic nuclear power plants. 

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. The fluid streams addressed are the coolant of a boiling water reactor (BWR), the coolant of a pressurized water reactor (PWR), and PWR steam generator fluids. The concentrations in fluid streams of BWRs and PWRs are treated in a similar manner but have different numerical values because of the differences in design.

A copy of ANSI/ANS-18.1-2016, in print or PDF format, is available on the ANS Store.