<P> The Three Mile Island accident occurred on March 28 , 1979 , in reactor number 2 of Three Mile Island Nuclear Generating Station ( TMI - 2 ) in Dauphin County , Pennsylvania , near Harrisburg . It was the most significant accident in U.S. commercial nuclear power plant history . The incident was rated a five on the seven - point International Nuclear Event Scale : Accident with wider consequences . </P>
<P> The Three Mile Island accident occurred on March 28 , 1979 , in reactor number 2 of Three Mile Island Nuclear Generating Station ( TMI - 2 ) in Dauphin County , Pennsylvania , near Harrisburg . It was the most significant accident in U.S. commercial nuclear power plant history . The incident was rated a five on the seven - point International Nuclear Event Scale : Accident with wider consequences . </P>
when did the three mile island accident happen
when did the three mile island accident happen
March 28 , 1979
March 28 , 1979