High Sensitivity Sampling and Analysis of Gaseous Radwaste Effluents

The regulatory agencies and federal codes stipulate certain minimum levels of sensitivity for the sampling and analysis of effluents from nuclear facilities. A device for enhancing sample concentration was designed and installed in the gaseous radwaste system of an operating nuclear power plant. A 180-liter gas sample was compressed into a small calibrated container for gamma spectroscopy. The resulting spectra were analyzed by an on-line programmable calculator with consideration given to offgas system delay times and fission yields for various components in order to accurately establish minimum detection limits. The data from a single sample is correlated with the continuous effluent monitor readings to determine the quantity of radionuclides released for a period of one month.