January 18 2013 Massachusetts Nuclear Event: The owner of the Pilgrim nuclear power plant has told the federal Nuclear Regulatory Commission that radioactive tritium has been discovered in a newly installed groundwater monitoring well at the plant.

Event date: 04:15:27 AM 18/01/2014
Event: Nuclear Event
Country: USA
State: State of Massachusetts
Area: Pilgrim Nuclear Generating Station
City: Plymouth

Short details: The owner of the Pilgrim nuclear power plant has told the federal Nuclear Regulatory Commission that radioactive tritium has been discovered in a newly installed groundwater monitoring well at the plant.

A sample taken from the well Dec. 30 indicated a tritium concentration of 69,000 picocuries per liter.

Those levels dropped to 20,000 in samples taken Jan. 6 and to 14,300 after additional samples were obtained Jan. 9.

The EPA limit for tritium in groundwater used for drinking purposes is 20,000 picocuries per liter. However, the groundwater at the Pilgrim site is not used for drinking. In 1991, the EPA calculated it would take a year-long ingestion of water containing 60,900 picocuries per liter of tritium to yield a radiation exposure dose of 4 millirems, a fraction of the approximately 620 millirems of radiation exposure that Americans receive each year from natural and man made sources.

Last April, Entergy identified a separation in its neutralizing sump discharge line. The company theorized, at that time, that this line was the source of tritium groundwater contamination first identified years earlier at the site. The new monitoring well is adjacent to the catch basin where the outfall from the sump discharge line was rerouted, which supports that theory.

However, the NRC also said that additional monitoring will be necessary before it can conclusively rule out other possible sources. The NRC will continue to inspect and report on the company’s implementation of its groundwater monitoring and prevention activities, as specified by the Nuclear Energy Institute’s Groundwater Protection Initiative. In addition, any subsurface contamination will be reviewed to ensure that public health and safety are protected.

Tritium is a radioactive isotope of hydrogen and is produced primarily by nuclear fission. Because it emits light in the dark, it can be used in exit signs, watch dials and some gun sights. It is also used to boost the yield of nuclear weapons. ...