Browns Ferry operators discovered a drain line from the condensate head tank was discharging a small amount of water containing tritium along the edge of the containment building on Saturday. As soon as the situation was identified, the Browns Ferry team took immediate action to close off all flow to the head tank lines, as well as contain and clean up the material, said Jim Hopkins with TVA. He said they are still determining the actual amount of water involved, but preliminary indications are between 100-200 gallons.
"At the point the water was sampled, the tritium level was above the EPA drinking water standards. However there has been no indication this material has left the immediate area of the containment building," said Mr. Hopkins. "We are continuing to sample for tritium in all off-site plant discharges but we have not seen any elevated tritium levels."
Tritium is a radioactive form of hydrogen that occurs in nature, as well as a by-product of nuclear fission. It is commonly used in several commercial operations for its luminsent abilities, including building "exit" signs and watch faces. Although any radioactive material should be appropriately managed, tritium is among the least energetic beta radiation emitters, which can be effectively blocked by a single piece of paper, according to Mr. Hopkins.
"Again, we have not discovered any elevated tritium levels in the intake or outflow of river water used as part of the cooling process at Browns Ferry," said Mr. Hopkins. "In the unlikely event any of the tritiated water enters either the intake or outflow channels, it would be significantly diluted in the two million gallons per minute flowrate and would rapidly drop to well below EPA drinking water standards. Based on all of these factors, there is no danger to the public or plant workers."
TVA is continuing the investigation and will be cooperating with both the NRC and state radiation health officials.