The potential dose of radiation a resident could receive from Savannah River Site rose slightly in 1999, according to an annual report written by the site.
The rise occurred in spite of reduced radioactive emissions and releases from the federal nuclear-weapons site, stated its 1999 environmental report.
The potential dose remained far below federal standards intended to protect public health, the report stated.
The maximum possible dose a resident could have received in 1999 was 0.28 millirem, compared to the 1998 dose of 0.19 millirem, the report stated. The federal limit is 100 millirem.
A millirem is one-thousandth of a rem. Rem, or roentgen equivalent man, is the unit of measure used to track doses of radiation in humans.
People receive a dose of about 1 millirem per day from natural and man-made radiation. A chest X-ray imparts a dose of about 8 millirem.
The rise in the possible dose from SRS during 1999 is caused by low water levels in the Savannah River, said Jim Heffner, deputy manager of environmental protection for Westinghouse Savannah River Co. Westinghouse operates the site for the U.S. Department of Energy.
The amount of radioactive tritium discharged into the river dropped, from 10,600 curies in 1998 to 6,290 curies in 1999, Mr. Heffner said. But lower river levels meant the tritium is more concentrated per liter of water, increasing the dose people could receive, he said.
The site released 51,600 curies of tritium in the air during 1999, a 38 percent drop from 1998's total of 82,700 curies, the report stated.
Other items included in the report:
The site twice was found in violation of the Clean Water Act, but attained an overall compliance rate of 99.8 percent. Of 5,778 analyses performed on water from the site, 10 exceeded permitted limits.
The site twice was found in violation of the federal Resource Conservation and Recovery Act, which regulates management of hazardous waste.
The site paid a penalty of $39,840 for one violation, which concerned a tank used improperly to store flammable solvent.
The site earned a compliance rate of 100 percent under the Clean Air Act, with no violations.
SRS has finished remediating 221 of its 515 known waste sites.
Reach Brandon Haddock at (706) 823-3409.