NEW YORK - Entergy Corp's 995-megawatt Unit 2 at the Arkansas Nuclear One power station in Arkansas was shut as of early Wednesday, the U.S. Nuclear Regulatory Commission said in its daily reactor status report.

On Tuesday, the unit was operating at full power.

The reason for the shutdown was not immediately known.

The 1,838 MW Arkansas Nuclear One station is located in Russellville in Pope County, about 75 miles northwest of Little Rock. There are two units at the station, the 843 MW Unit 1 and the 995 MW Unit 2, which entered service in 1974 and 1980.

Unit 1 continued to run at full power.

One MW powers about 500 homes in Arkansas.

Entergy, of New Orleans, owns and operates about 30,000 MW of generating capacity, markets energy commodities and transmits and distributes power to 2.7 million customers in Arkansas, Louisiana, Mississippi and Texas.