NRC file photo of the twin reactors at Calvert Cliffs on the Chesapeake BayNational Public Radio station WAMU at American University in Washington, DC has reported that the U.S. Nuclear Regulatory Commission (NRC) has increased inspection levels at Baltimore-based Constellation Energy's Calvert Cliffs nuclear power plant in Lusby, Maryland on the Chesapeake Bay due to security related violations of regulations deemed by NRC to be of "moderate" safety significance. Calvert Cliffs is the closest nuclear power plant to the nation's Capitol, about 50 miles or less from the District of Columbia. WAMU also mentioned the shut down of one of Calvert Cliffs' two reactors when Hurricane Irene's winds tore aluminum siding from the turbine building and drove it into a main transformer, as well as an incident last winter in which melting snow leaking through the roof short circuited electrical equipment, forcing both reactors to shut down.