The share of Tokyo Electric Power Co., the operator of a stricken nuclear power plant, plunged as much as 15 percent to the lowest Tuesday, April 5, 2011, since its listing in Tokyo Stock Exchange Market in August 1951. The decision by the utility giant to dump radioactive water from its crippled Fukushima No.1 nuclear station, located some 120 miles northeast of Tokyo, into the sea not only angered fishermen but also pushed the company shares to the record low.