Here is a list of major atomic power plant accidents reported outside the United States:
--A serious nuclear accident occurred in the Soviet Union during the winter of 1957-58, according to a U.S. report published more than two decades later. In February 1980, the Oak Ridge National Laboratory in Tennessee, using CIA data and Soviet scientific publications, corroborated claims by an exiled Soviet scientist that a wide area of the central U.S.S.R. was contaminated by radiation from an accident near Kasli, 190 miles north-northeast of Magnitogorsk, in Chelyabinsk Province on the eastern side of the Ural mountains. The report said the contamination covered anywhere from 40 to 400 square miles. It said there was ''some loss of life'' and at least 30 villages were abandoned, their names subsequently deleted from Soviet maps.
--On Oct. 10-11, 1957, an overheated reactor at Britain's Windscale plutonium production plant in Cumberland burned for 24 hours, leaking radioactive iodine that contaminated 200 square miles and prompted a temporary government ban on milk in the area. A government report later said the accident posed no health threat.
--On April 28, 1986, the Soviet Union acknowledged an accident occured at a nuclear power plant in Chernobyl, 80 miles north of Kiev, and that a reactor was damaged. The Soviet report came after the governments of Sweden, Finland, Denmark and Norway said a cloud of non-lethal radioactive material had swept across the regions over the previous two days.