Operators at Oyster Creek Generating Station reduced power on the unit overnight to allow plant teams access to make repairs to a six-inch pipe that penetrates the turbine building. The station is currently operating at about 50 percent power.
After station operators identified a leak inside the turbine building late Monday, technicians proactively began excavating the area outside the turbine building to check for water outside the building as part of the station's environmental monitoring program.
Station operators know most of the water from the pipe, which passes through a 4-foot-thick concrete wall, is confined to the turbine building. Samples taken from the excavation returned elevated concentrations of tritium, indicating some of the water may have made its way into the soil immediately adjacent to the structure. Plant teams are taking immediate actions to stop the leak.
"While this is not a public or employee safety issue, we identified this leaking pipe and are immediately taking steps to make the necessary pipe repairs," said Mike Massaro, Site Vice President of Oyster Creek Station. "We quickly contacted federal and state regulators with our findings and will continue to keep them and the greater Oyster Creek community informed as we repair the pipe."
Water samples taken daily from the plant's discharge canal continue to show no detectable levels of tritium. Samples taken from the excavation contain tritium levels up to 10 million picocuries per liter of water. A picocurie is one trillionth of a curie. The excavation is near the area where plant teams found and stopped two small leaks in April. At that time, station operators replaced an eight-inch pipe and a ten-inch pipe, and they continue to inspect pipes in the area as part of the site's aging management program.
Massaro said station and corporate engineering experts are currently evaluating the best environmental course in rerouting the pipe above ground, or to construct a vault around the pipe.
Tritium is a weak, naturally occurring radiation emitter that is used commercially to make luminous dials and instruments, as a source of light for exit and safety signs, as a tracer for biochemical research and in ground water transport measurements, among other uses. It is produced in higher than natural concentrations in commercial nuclear reactors. A tritium fact sheet from the U.S. EPA can be downloaded at http://www.epa.gov/radiation/radionuclides/tritium.html
Oyster Creek is about 60 miles east of Philadelphia in Ocean County, New Jersey. The plant produces 636 net megawatts of electricity at full power, enough electricity to supply 600,000 typical homes, the equivalent to all homes in Monmouth and Ocean counties combined.