Federal regulators Friday pushed back their timetable to make a decision on Southern California Edison's proposal to restart the Unit 2 reactor and run it at reduced power.
Nuclear Regulatory Commission officials said earlier that a ruling could come in March.
But the NRC has delayed that decision until at least late April or May.
The plant between San Diego and Los Angeles hasn't produced electricity since a tiny radiation leak in January last year led to the discovery of excessive wear on hundreds of steam generator tubes that carry radioactive water.
Edison predicts running at low power will stop tube damage.
Environmentalists say the plant cannot run safely.