(Reuters) - Severe storms and tornadoes moving through the Southeast dealt a severe blow to the Tennessee Valley Authority on Wednesday, causing three nuclear reactors in Alabama to shut and knocking out 11 high-voltage power lines, the utility and regulators said.
All three units at TVA's 3,274-megawatt Browns Ferry nuclear plant in Alabama tripped about 5:30 EDT (2230 GMT) after losing outside power to the plant, a spokesman for the U.S. Nuclear Regulatory Agency said.
A TVA spokeswoman said the plant's output had reduced power earlier due to transmission line damage from a line of severe storms that spawned a number of tornadoes as it moved through Mississippi, Alabama, Kentucky and Tennessee.
The NRC spokesman said early information indicated the units shut normally and the plant's diesel generators started up to supply power for the plant's safety system.
The government owned corporation said crews were working to restore service, but more severe weather was forecast, TVA said in a release.
Most of the damage so far has occurred in the western part of TVA's service territory in Mississippi, Alabama and western Tennessee and Kentucky.
Cullman Electric Cooperative in Cullman, Alabama, is the only power company directly affected by TVA's transmission outage, TVA said in a statement.
Rainfall amounts between four and seven inches have fallen since Tuesday in the area. Eight of the nine dams on the Tennessee River were generating at full power to move water through the river system to help control flooding, TVA said.
Details of the transmission outages and co-op power outages were immediately available.
(Reporting by Eileen O'Grady; editing by Marguerita Choy and Andre Grenon)