UPDATE 1-PG&E Calif. Diablo Canyon 1 reactor back

(Updates with company comment)

NEW YORK, Sept 22 (Reuters) - PG&E Corp's (PCG.N) 1,122-megawatt Unit 1 at the Diablo Canyon nuclear power plant in California returned to service, the company said in a release early Tuesday.

The unit shut by Sept. 21 to fix one of six feedwater heaters, which are part of the system that supplies feedwater to the unit's steam generators.

All six feedwater heaters are necessary to continuously operate at full power.

The 2,240 MW Diablo Canyon station is located in Avila Beach in San Luis Obispo County about 195 miles northwest of Los Angeles. The station has two units, 1,122 MW Unit 1 and the 1,118 MW Unit 2, which entered service in 1985 and 1986.

Unit 2, which was expected to shut in early October for a planned month long refueling outage, continued to operate at full power.

One MW powers about 700 homes in California.

PG&E, of San Francisco, owns and operates more than 6,200 MW of generating capacity, markets energy commodities, and transmits and distributes electricity to almost 5.3 million customers and natural gas to 4.2 million customers in California. (Reporting by Scott DiSavino)