The Unit 1 reactor at the San Onofre nuclear power plant has been shut down for unscheduled repairs, a utility spokesman said. There was no emergency and no release of radiation, said David Barron, spokesman for Southern California Edison Co. The utility operates the power plant on the coast about 60 miles south of Los Angeles. "There is no hazard associated with the outage to plant employees or the public," Barron said. The Unit 1 reactor, which has an electrical generating capacity of 450,000 kilowatts, was operating at about 40% power, Barron said. Repair crews had been working to repair a discharge valve in the plant's coolant system, which is among the reactor's non-nuclear equipment, when they decided to shut down the unit.