No radiation limits exceeded at VY in 2010
BRATTLEBORO - According to the Vermont Department of Health, there were no instances where radiation emissions from Vermont Yankee nuclear power plant in Vernon exceeded state limits in 2010.
The DOH's radiation surveillance report for Yankee was published on its website on Wednesday.
"There were no instances of non-compliance with the Radiological Health Rule from either operations at Vermont Yankee or the tritium-contaminated plume of groundwater first reported in January 2010," stated the report.
The purpose of the surveillance, which has been conducted since plant startup in 1970, is to assure that the public's health is protected from excess amounts of radiation.
Environmental measurements are taken at various locations throughout the year, which are compared to background radiation, past measurements and state regulatory limits. In 2010, more than more than 1,600 samples of air, water, milk, soil, vegetation, sediment and fish were taken at the Yankee property line, on-site, from the Connecticut River and from the towns surrounding the station.
In addition to monitoring radiation and radioactive effluents from the plant, DOH also conducts a continuing analysis of cancer statistics for people who live in the communities surrounding Yankee.
The most current analysis concluded cancer incidence and mortality do not differ significantly from people in the rest of Windham County, elsewhere in Vermont, or the United States as a whole, according to the report.
DOH also reported on the discovery of strontium-90 in fish taken from the Connecticut River.
"Results for 2010 are similar to those previously reported," stated the report. "Fish had measurable amounts of potassium-40, a naturally-occurring radioactive material, strontium-90 and cesium-137, both human-made radioactive materials. Levels of cesium-137 detected are within the historical range for Vermont of below the lower limit of detection to 100 picocuries per kilogram."
The report stated no historical range has been established for strontium-90 in Vermont fish.
"However, one finding was notable: Strontium-90 was detected just above the lower limit of detection in the edible portion of one fish sample collected in June," noted the report. "This was the first time that strontium-90 has been detected in the edible portion of any of the fish samples."
Scientific literature indicates that strontium-90 can accumulate in edible portions of fish over time, stated the report, but this finding requires more sample data to better understand what it means.
The levels of radioactive materials measured in these fish do not pose a health risk.
DOH also conducted more frequent environmental sampling during April through June 2011 in response to the accident at Fukushima Nuclear Power Station in Japan in March 2011.
"Trace amounts of cesium-137 and iodine-131 were detected in samples taken in Vermont," stated the report. "These results were expected following the events in Japan. There is no health risk to Vermonters."
The state's Radiological Health Rule limits the amount of ionizing radiation that a member of the public could be exposed to if standing at the property line of the station.
The rule also limits the amount of gaseous, liquid, radioiodine and radioactive particulate effluents that a member of the public could possibly be exposed to as a result of the plant's operation.
The rule specifically limits the annual direct gamma radiation from Yankee to a measured exposure value of 20 milliroentgen above background radiation at the site boundary on land, or a 5 millirem effective dose equivalent to any member of the general public.
Specific emissions or discharges from Yankee are also limited to an effective dose of no more than 5 millirem from each pathway to any member of the general public.
The Nuclear Regulatory Commission limits the annual direct gamma radiation to any member of the general public at the plant's boundary to 100 millirem.
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