Samples from a newly drilled monitoring well at the Callaway nuclear plant in Missouri showed levels of tritium and cobalt-60 at concentrations that exceed limits for drinking water.
In a report filed with the Nuclear Regulatory Commission (NRC), the Ameren plant said the contamination did not actually affect drinking water and did not result in an increased dose among the public or plant employees.
Nonetheless, Callaway scheduled additional sampling and notified county and state officials. The Westinghouse four-loop pressurized water reactor near Fulton, MO, continued to operate at full power.
On Thursday, the plant received the analysis of a sample taken July 25 indicating the presence of tritium at 1.6 million picocuries per liter and Co-60 at 12 pCi/L, according to the NRC.
The EPA limit for tritium in drinking water is 20,000 pCi/L, provided the total dose from all radionuclides present does not exceed 4 millirem per year. The EPA limit for cobalt and other beta-emitters is 8 pCi/L.