PPL Corp. has begun increasing the capacity of a Pennsylvania nuclear power plant, the electricity provider said Tuesday.

In late January, the Nuclear Regulatory Commission approved PPL (nyse: PPL - news - people )'s request to increase the plant's total electrical output by 205 megawatts. A one-megawatt plant running continuously at full capacity can power 778 households each year, according to the U.S. Department of Energy.

Early Tuesday workers at PPL's Susquehanna nuclear power plant safely shut one of the plant's two reactors to replace uranium fuel, begin maintenance work and replace a steam dryer so the reactor can produce more electricity.

The work on Unit (nyse: UNT - news - people ) 1 is expected to be completed by mid-April. Meanwhile, the plant's other unit continues to operate at full power.

The plant modifications needed to hike output at the Susquehanna plant will be completed in phases, all of which are expected to be completed by 2010.

The plant is owned jointly by PPL Susquehanna LLC and Allegheny Electric Cooperative Inc. and is operated by PPL Susquehanna.

PPL, which controls more than 11,000 megawatts of generating capacity in the U.S., will own 185 megawatts of the Susquehanna plant's additional generation. Allegheny Electric Cooperative will own the rest.