Southern California Edison, which owns the plant along with San Diego Gas & Electric and the city of Riverside, is performing safety inspections and testing, Craver said.The company expects to deliver a plan to the Nuclear Regulatory Commission by the end of July regarding the operation of the plant's Unit 2, Craver said. The commission, which must approve the restart of Unit 2, will then need time to respond, Craver said.A plan for Unit 3 is expected to take longer to develop, Craver said."It is a significant amount of power that's being lost," said San Diego State University professor Murray Jennex, who worked at San Onofre as an engineer. Jennex told 10News the San Onofre plant generates nearly 20 percent of San Diego County's electricity. "If it gets a real hot streak, that's when you probably will have to be concerned," said Jennex. The shutdown was necessitated by a leak detected in a tube in Unit 3 on Jan. 31. The problem resulted in a minor venting of radioactive gas, according to Southern California Edison officials, who reported that the release was detectable only on sensors in an adjacent building and posed no hazards to plant workers or the public.Unit 2 was taken down for planned maintenance Jan. 9 and remains off-line.Unit 1 was in operation from 1968 to 1992, when it was shut down over fears it could not withstand a major earthquake.To restart a generator, Southern California Edision has to submit a safe plan to federal regulators. However, that will not happen until the beginning of August, at which time regulators then need weeks to study it. More than 7 million people live within 50 miles of the plant, which can power about 1.4 million homes. The timing of could not be worse for the plant to be down through August, when average inland temperatures in San Diego can reach the mid-90s. Air conditioning use during peak hours can nearly double power consumption over the times of the year when air conditioning is not used. SDG&E says contingencies have already been activated. The final tower of the Sunrise Powerlink went up earlier this week, and the link is supposed to be online by the end of June.Additionally, a retired power plant in Orange County has already been restarted. Should rotating outages become necessary, SDG&E says they typically last about an hour during peak demand and do not affect essential customers such as hospitals and fire departments. "Don't run your appliances until after 7 during the hot times; minimize your use as much as possible," Jennex recommended. The first in a series of public meetings with San Onofre plant officials and federal regulators is scheduled for June 18 at 6 p.m., at the San Juan Capistrano Community Center on 25925 Camino Del Avion, in San Juan Capistrano.