UPTON, NY - The U.S. Department of Energy's Brookhaven National Laboratory recently measured unexpected levels of tritium at its sewage treatment plant. The tritium concentration in the sewage effluent peaked last week between Thursday and Friday at a high of about 67,000 picocuries per liter (pCi/l), well above what is normally measured in the effluent.
BNL has notified county, state and federal regulators. DOE and BNL are aggressively searching for the source.
As part of routine sampling of the sewage effluent, the Thursday sample was analyzed over the weekend, and the Friday, Saturday and Sunday samples were analyzed yesterday. Reanlysis was also done yesterday to verify initial results. Based on the data so far, the release was a one-time occurrence, and the tritium concentrations in the effluent are now returning to normal.
On average every month, the sewage treatment plant effluent contains tritium at a concentration of about 2,000 pCi/l. The Laboratory sets a monthly administrative discharge goal for the plant at 10,000 pCi/l. Including the most recent high values, the average tritium concentration for the month of July is 5,100 pCi/l.
The sewage treatment plant discharges on average two to three curies of tritium per year. The recent release contained approximately 0.2 curie, or two-tenths of one curie.
Tritium, a radioactive isotope of hydrogen, is produced as a byproduct in a variety of research projects at the Laboratory. It is routinely released in low concentrations to the BNL sanitary system, and sanitary waste is finally collected at the sewage treatment plant. The high levels that passed through the plant last week are not normal.
BNL's sewage treatment plant discharges on site to the Peconic River. Over the past decade, because of drought conditions on Long Island, the river bed upstream of the plant outfall has been generally dry. BNL's discharge, which is roughly one million gallons a day, creates a small stream, which usually goes dry before reaching the Laboratory's border.
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