After a three-month investigation, the NRC announced earlier this year that a botched computer analysis resulted in design flaws that caused excessive vibration and resulted in heavy wear in many tubes.
Edison's proposal calls for operating Unit 2 at up to 70 percent power, which engineers believe will stop the vibration. It would run for five months, then be shut down for inspections. The future of its twin reactor, the heavily damaged Unit 3, is unclear.
Anti-nuclear activists have argued for months that restarting the plant, located between San Diego and Los Angeles, would invite catastrophe. About 7.4 million Californians live within 50 miles of San Onofre's twin domes.
In a March letter, federal regulators outlined a series of benchmarks Edison must reach to restart the plant, including determining the cause of vibration and friction that damaged scores of generator tubes, and how it would be fixed and then monitored during operation.