Hitachi (hētäˈchē) [key], city (1990 pop. 202,141), Ibaraki prefecture, E central Honshu, Japan, on the Kashima Sea. The city, a leading producer of Japan's electrical equipment, is the largest commercial port in the prefecture. A nuclear fuel plant in Tokaimura, 15 mi (24 km) southwest of Hitachi, was the site of an accident involving an uncontrolled chain reaction in 1999. The tsunami that followed the 2011 NE Honshu earthquake damaged Hitachi's port, but other parts of the city were largely unscathed.