Rapid determination of noble gas radionuclide concentrations in power reactor plumes

Calibration procedures and measurement protocols are described for taking in situ high resolution gamma-ray spectra in the vicinity of nuclear installations. These spectra can be analyzed to calculate the release rates, the ground-level air concentrations and the resultant exposure rates for individual radionuclides in the effluent plume. Standard Gaussian cloud concentration models are used for the source geometry and the methods may be readily adapted to existing spectrometer systems. An example application of the method to a gamma-ray spectrum taken near a large boiling water reactor BWR is presented.