Unit 2 at the Susquehanna nuclear power plant near Berwick returned to service Friday (4/21) after a six-day outage.

The unit shut down automatically April 15 after an unexpected opening of a main electrical circuit breaker at a 500,000-volt substation, according to Herbert D. Woodeshick, special assistant to the president for Pennsylvania Power & Light Co.

Electricity generated by Unit 2 is transmitted through the substation on its way to PP&L customers.

"After a thorough investigation, we found and corrected a mechanical setting on a relay device used for protection of electrical equipment," Woodeshick said. "Our action will prevent this equipment from leading to future shutdowns."

PP&L used the opportunity to complete other maintenance jobs on Unit 2 that can be done only when the unit is out of service.

Unit 1 at the plant remains out of service for scheduled refueling and maintenance.

The Susquehanna plant, located in Luzerne County about five miles north of Berwick, is owned jointly by PP&L and Allegheny Electric Cooperative Inc.