SAN DIEGO -- Two Southern California utilities said Thursday they have agreed in principle to shut down the oldest of the three San Onofre nuclear power plants by the middle of next year.
The move by the utilities -- San Diego Gas & Electric Co. and Southern California Edison Co. -- came in response to concerns that the 24-year- old plant had become too outmoded to operate efficiently.
'The plant has had quite a problem with needing to be upgraded over the last 10 years to meet current operating requirements,' said Robert Kinosian of the ratepayer advocates arm of the California Public Utilities Commission, which hammered out the agreement with the utilities.
The 450-megawatt plant had been operating 44 percent of the time during the past five years, SDG&E said. During 1991, the plant operated 68 percent of the time.
Edison, which is based in Rosemead, operates the plant and owns 80 percent of it. SDG&E owns the remaining 20 percent.
Kinosian said the facility was opened at a cost of about $100 million in 1968. At that time, the requirements for operating a nuclear plant were much less stringent, he said.
The ratepayers arm, which held public hearings on the future of the plant last fall, has said it would cost $125 million in improvements over the next two years to keep the plant running with little guarantee it would operate efficiently.
The utilities have disputed that contention. 'This was a tough decision for us, because we believe that we still could operate the plant efficiently,' said Stephen Baum, general counsel for SDG&E.
'We feel this is a compromise that balance the interests of all the parties,' Baum said.
The decision, which must still be approved by the five-member Public Utilities Commission, does not affect the other two 1,100-megawatt nuclear power plants at San Onofre, located on the coast about 50 miles north of San Diego.
Kinosian said that the other two plants, which were opened in 1983 and 1984, have been able to operate at rates of above 80 percent.
Kinosian said the commission would probably approve the closure of the oldest plant, called San Onofre Nuclear Generating Station 1 or SONGS-1, within the next four months.
The agreement will allow the utilties to charge customers $450 million over the next four years to recoup their investment in the plant. Customers of Edison will pay $350 million and customers of SDG&E will pay the rest.
SONGS-1 will be allowed to operate until its current fuel supply runs out, which will occur at the end of this year or, if the utilities can reconfigure the plant, in the middle of 1993.
The entire San Onofre facility, which employs about 400 workers, has been criticized by environmentalists concerned about the proximity of nuclear fuel to millions of people and the effects of using ocean water to cool the reactors. The newer units use an estimated 2 million gallons of water per minute.
Earth Island Institute and two of its members, David Jeffries and Donald May, filed a federal suit in San Diego against Edison in late 1990 seeking penalties and an injunction against the utility. A trial date has been set for next December.
The suit alleges that the water intake is killing small fish and fish larvae and that the release of the water is destroying kelp beds near the plant.
