The outage at the San Onofre Nuclear Generating Station (SONGS) looks as though it will continue into the summer, which will affect the electricity outlook for local areas in Southern California, according to recent reports.
Investigators are still trying to determine why tubes carrying hot, pressurized, radioactive water inside the relatively new steam generators are deteriorating at a dangerous and unusual rate. A team of federal investigators was dispatched to the San Diego-area plant earlier this month. Inspectors with the Nuclear Regulatory Commission say they will hold a public meeting when the inspection is complete.
Last month, San Onofre unit 3 was taken out of service because of a leaking steam generator tube that resulted in a small release of radioactive steam into an auxiliary building. On Thursday initial reports from NRC inspectors also outlined wear in similar equipment at neighboring unit 2. During a scheduled outage for maintenance and inspections, the NRC found the thickness of two tubes in one of unit 2's two steam generators had been worn away by a third. Of 9,700 tubes in the steam generator, 69 were found to be at least 20 percent worn, and 800 tubes were at least 10 percent worn.
Last week, three steam generator tubes in unit 3 failed during recent in-situ tests, resulting in further scrutiny from federal regulators.
In a report presented to the ISO board Thursday, staff said in the event of a worst-case scenario like a major heat wave or transmission line outage during the peak season, the San Diego and Los Angeles areas could face energy shortages without the 2,200 megawatts of power generated by San Onofre.
"Safety is the top priority during ongoing inspections and testing of the nuclear power plant," said ISO President and CEO Steve Berberich. "Our focus is contingency planning should SONGS remain offline this summer. Fortunately, there are resource options available to help mitigate reliability risks. We are actively working with San Diego Gas & Electric, Southern California Edison and others because prudent mitigation planning takes adequate lead time and summer heat is only a couple months away."