Environmental measurements at the Savannah River Site with underwater gamma detectors

Underwater gamma-ray detectors and NaI and HPGe detectors were installed in the Savannah river to monitor effluent releases from the Savannah river site and Plant Vogtle nuclear power stations and to distinguish between the effluents of the 2 sites. During 1987-1992, the 811 keV count rate of cobalt-58 obtained using the NaI detector was correlated with releases reported by Plant Vogtle. Release magnitudes decreased with time. Caesium-137 was the dominant gamma-emitting radionuclide in pond sediments. Pond radioactivities were adequately quantified by 1 minute counts with the HPGe detector.