ATLANTA - A nuclear power plant operated by The Southern Co. will face more federal inspections because the electronics controlling an emergency power system on one of its reactors failed to work, federal regulators said Friday.

The problems affected an automatic control system for one of the diesel generators attached to a nuclear reactor at Plant Hatch near Baxley in southeast Georgia. The commission said the problem was a low-to-moderate safety risk and ordered an additional round of inspections since it previously identified another problem at the plant related to an emergency diesel generator.

In a February report, NRC inspectors said the plant failed to satisfy preventive maintenance requirements on parts of the electrical system that automatically start up the backup diesel generators. The power plant relies on power from those generators to safely shut down its nuclear reactor should the plant lose electricity.

Southern Co. has not been fined for the violation, although it must pay for the cost of the additional inspections, NRC spokesman Joey Ledford said.

Southern Co. spokeswoman Alyson Fuqua said the root problem was with several 10-inch by 5-inch electronic cards that are supposed to automatically start up emergency generators outside Hatch's second reactor, which began operating in 1979.

The company first identified the problem during a test in February 2009 when the electronics failed to automatically start an emergency generator and did not set off the appropriate alarms in the plant's control center, Fuqua said.

Power plant crews refurbished all the electronic cards and fixed the problem earlier this year, she said. Those cards are now inspected more frequently.

While the Southern Co. acknowledges the cards did not work, it disputes that the glitch seriously compromised the plant's safety since workers in the control room could manually start the backup power generators.

"We felt very strongly that even if this was to .... happen in a real event, the operators could manually control the situation and start the generators from the control room," Fuqua said.

The NRC is requiring extra inspections since the most recent problem followed another issue involving an emergency diesel generator. In July 2009, federal regulators cited the plant for having a degraded coupling between the engine of a diesel generator and the portion of the system that produces electricity.