Three Mile Island notifies regulators of intent to close

The owners of the Pennsylvania's Three Mile Island nuclear plant have formally notified regulators and a regional power grid operator of their previously announced intentions to close the plant.

LNP newspaper reports Exelon Corp. sent a letter June 20 to the Nuclear Regulatory Commission saying the plant would be shut down around Sept. 30, 2019 due to "severe economic challenges."

Exelon criticized electrical grid operator PJM Interconnection in a May 30 letter to the company saying PJM has not adapted to changes in the energy market. It said market rules don't value the "clean, resilient" electricity provided by the plant.

The plant was the site of the United States' worst commercial nuclear power accident, a 1979 partial core meltdown of one reactor. The other reactor is still in use.