Researchers have discovered small quantities of a radioactive substance in material dredged from Savannah Harbor about 100 miles downstream from the Savannah River Plant. Cesium 137, a radioactive isotope, was found in material taken from the harbor and dumped on the South Carolina side of the Savannah River, which forms the border with Georgia. Tests found tiny amounts of the material, insufficient to create a health hazard, The Charleston News & Courier reported today. The tests were done for the South Carolina Wildlife and Marine Resources Department by researchers at the University of Georgia. The wildlife agency is sampling dredged material for pollutants because of water quality problems believed to be caused by industrial discharges into the river, agency officials said. Cesium 137 is produced as a byproduct of nuclear fission, and is generally associated with radioactive waste. It emits beta and gamma radiation, both of which can produce a variety of ill effects, depending on the dosage. Lou Gordell, acting director of the U.S. Department of Energy's environmental division at the nuclear plant, said he had not been informed of the study results, but acknowledged Monday that the material probably originated at the Savannah nuclear plant. The complex near Aiken produces the radioactive materials plutonium and tritium for nuclear weapons. The government-owned plant has been under scrutiny in recent months since it was revealed that a series of accidents at the site over the past 30 years went unreported to the public. Gordell said sediment tests in Savannah Harbor for a 1984 study showed traces of Cesium 137, and that recent monitoring upstream found similar traces both in the water and river sediment. Much of the material leaked from SRP apparatus in the 1950s, but some is the result of continued discharge into the river, Gordell said. The level of contamination is far below EPA's maximum allowable level for drinking water, he said. Savannah and Beaufort-Jasper counties pump water from the Savannah River for drinking water. Traces of tritium also are found in the river, but also are below the maximum allowable levels, Gordell said. Cesium 137, with a half-life of 30 years, persists in the environment longer than tritium, with a half-life of 12 years. A half-life is the time it takes half the atoms of a radioactive material to disintegrate. The Savannah Harbor is periodically dredged by the U.S. Army Corps of Engineers to maintain its depth for the port of Savannah.
