Calvert Cliffs Unit 1 coming back online

Unit 1 of the Calvert Cliffs nuclear plant in Maryland, which is operated by Exelon (NYSE:EXC), is coming back online after experiencing an unplanned outage during the recent winter storm on the East Coast.

The unit was listed at 30% generation in the Nuclear Regulatory Commission (NRC) reactor status report issued early Jan. 26. The unit synched to the grid at about 1:26 a.m. ET, a company spokesperson said.

Operators had removed Unit 1 from service over the wintry weekend. Company officials said workers were to perform electrical maintenance in the switchyard that distributes power from the station to the grid.

Over the weekend, high winds and ice accumulation caused a high-voltage line to disconnect in the Unit 1 switchyard. Operators needed to de-energize the line in order to make repairs, which required that the generator be taken off line.

Unit 2 continued to run at full power.

Calvert Cliffs is located on the western shore of the Chesapeake Bay in Calvert County and is Maryland’s only nuclear energy facility.  The station is home to two pressurized water reactors (PWRs) capable of generating 1,756 MW combined. Units 1 and 2 began commercial operation in 1975 and 1977, respectively.

Exelon currently owns 50.01% of Constellation Energy Nuclear Group (CENG), which is jointly owned with a U.S. affiliate of the French EDF Group. CENG currently holds the operating licenses for five nuclear power reactors at three plant sites – Calvert Cliffs 1 and 2, Nine Mile Point 1 and 2, and R.E. Ginna.

Exelon holds an option to buy out the EDF interest.

About Wayne Barber 4201 Articles
Wayne Barber, Chief Analyst for the GenerationHub, has been covering power generation, energy and natural resources issues at national publications for more than 20 years. Prior to joining PennWell he was editor of Generation Markets Week at SNL Financial for nine years. He has also worked as a business journalist at both McGraw-Hill and Financial Times Energy. Wayne also worked as a newspaper reporter for several years. During his career has visited nuclear reactors and coal mines as well as coal and natural gas power plants. Wayne can be reached at