The California Public Utilities Commission has launched an investigation into the nine-month outage at the San Onofre nuclear plant, which could result in rates eventually being lowered or money refunded to customers of the energy companies that own the plant.
The five commissioners voted unanimously to launch the probe at its meeting Tuesday in Irvine.
Commission President Michael Peevey promised that the investigation of the darkened plant -- on the coastline south of San Clemente -- will be "exhaustive."
The probe will look at the costs of the long-running outage, which resulted from defective replacement steam generators at the plant, and at the potential cost to ratepayers from repairs as well as scenarios in which one or both reactors never come back online.
According to the order adopted by the commission, ratepayers are paying more than $1.1 billion a year in costs related to the troubled plant.
The outage could add to that tab with the cost of studying the problem, repairs, replacement power and potential litigation between plant operator Southern California Edison and steam generator manufacturer Mitsubishi Heavy Industries.
Edison has submitted a proposal to the U.S. Nuclear Regulatory Commission to restart one reactor, where the issues were less severe, at partial power. The NRC must give approval before the plant can fire up again.
"Our primary responsibility is to look at the rate issues, and also look at the system," said CPUC Commissioner Catherine Sandoval. "How do we maintain safe and reliable power for Southern California at just and reliable rates?"
This story was reported by Times Staff Writer Abby Sewell.