Susquehanna Unit 1 Surpasses All Others as the U.S.’s Largest Boiling‑Water Reactor

Following the completion of equipment and system upgrades during the most recent scheduled refueling and maintenance outage, Unit 1 at PPL Corporation’s Susquehanna nuclear power plant in Luzerne County, Pa., has become the largest boiling‑water reactor in the United States by thermal power and electrical generating capacity, the Nuclear Regulatory Commission confirmed.

“PPL continues to invest in the future of the Susquehanna plant with upgrades that increase the amount of electricity the facility can safely produce,” said Jeff Helsel, plant manager.

When operating at full power, Susquehanna’s Unit 1 delivers 3,952 MW th of thermal energy and approximately 1,300 MW e of electrical power. PPL owns 90 % of the plant’s output, with Allegheny Electric Cooperative holding the remaining 10 %.

During the outage, workers installed a new integrated digital control system for plant equipment and replaced turbines that drive pumps supplying water to the reactor vessel. These upgrades enable Unit 1 to produce more steam and generate more electricity.

The upgrades are part of a four‑year project that began in 2008 and is slated to finish in 2011, once similar improvements to Unit 2 are completed. At that point, Unit 2 will match Unit 1’s thermal and electrical capacities.

“Susquehanna has a proven record of safe, reliable operation. Expanding its generating capacity is a cost‑effective way to meet future energy demand from an existing source that emits no greenhouse gases,” Helsel added.

Susquehanna is a two‑reactor plant of the boiling‑water design; the other common design in the United States is the pressurized‑water reactor. Located about seven miles north of Berwick, the plant is owned by PPL Susquehanna LLC and Allegheny Electric Cooperative Inc., and operated by PPL Susquehanna.

PPL Susquehanna is one of PPL Corporation’s generating facilities. Headquartered in Allentown, Pa., PPL controls or owns nearly 12,000 MW of generating capacity nationwide, sells energy in key U.S. markets, and delivers electricity to roughly 4 million customers in Pennsylvania and the United Kingdom.