PARIS - France's ASN nuclear safety authority said on Tuesday the nuclear accident at Tokyo Electric Power Co's Fukushima Daiichi plant could now be classed as level six out of an international scale of one to seven.
On Monday, the ASN had rated the ongoing accident at the plant, located 240 km (150 miles) north of Tokyo, as a five or six.
Level seven has been used only once, for Chernobyl in Ukraine in 1986. The 1979 accident at the Three Mile Island nuclear power plant in the United States was rated a level five.
"We are now in a situation that is different from yesterday's. It is very clear that we are at a level six, which is an intermediate level between what happened at Three Mile Island and Chernobyl," ASN President Andre-Claude Lacoste told a news conference in Paris on Tuesday.