But the effects of the plant’s closing are already reverberating. By September, Southern California Edison will reduce its staff at the plant to 600 employees from 1,500. Electricity prices have increased since the plant, which is about halfway between Los Angeles and San Diego and powered 1.4 million homes, went offline last year.

Last week, when the power went out at Lily Tally’s home in San Clemente, she worried that erratic electricity service — especially in the summer, when demand for power is highest — would become more common. She said she and her husband were now planning to put solar panels on their house.

Still, she said she was relieved that San Onofre was closing. Interstate 5, the only road out of town, runs beside the plant’s trademark twin domes. So Ms. Tally and her husband kept their S.U.V. ready in case they needed a different escape route. They planned to drive with their two young sons through the nature preserve east of town.

“It was always in the back of my mind, especially with the earthquakes here,” Ms. Tally, 35, said. “Safety-wise, I do feel better now. But then there’s the ambivalence about having other sources of power that will cost more.”

The rising cost of power is not the only concern for local businesses. In the non-summer months, seasonal plant workers often made up about 30 percent of the guests at some San Clemente hotels, although that number has dwindled since last year.

Nancy Hunt, a local real estate broker, said consultants, who would work at the nuclear plant for months at a time, also accounted for a large portion of the renters in town.

“The workers rent in our community. They go to the beauty shops here. They go to the restaurants,” Ms. Hunt said. “We will miss them.”