San Onofre Nuclear Generating Station
LOS ANGELES (AP) — A nuclear reactor on the California coast will remain shut down indefinitely while a team of federal inspectors determines why several relatively new tubes became so frail that tests found they could rupture and release radioactive water, a federal official said Thursday.
"This is a significant issue," said Nuclear Regulatory Commission spokeswoman Lara Uselding. "A tube rupture is really the concern. ... That's what we don't want to happen."
Underscoring concern over the test findings, the NRC dispatched a special team to the Unit 3 reactor at the San Onofre Nuclear Generating Station, located about 45 miles north of San Diego. The plant was shut down as a precaution on Jan. 31, after a radioactive water leak in another tube in a massive steam generator. Traces of radiation escaped, but officials say there was no danger to workers or neighbors.
The NRC said Thursday that pressure tests showed three of the metal-alloy generator tubes had become so degraded that they could rupture under some circumstances. Such ruptures can require a plant to shut down, if spewing water reaches 150 gallons a day.
Investigators have been looking into what federal officials call excessive wear found on steam generator tubes in the seaside plant and its twin, Unit 2, which has been off line for maintenance and refueling. In a $670 million overhaul, two huge steam generators, each containing 9,700 tubes, were replaced in Unit 2 in fall 2009 and a year later in Unit 3. Read more…
