The government's nuclear watchdog on Tuesday raised its assessment of the severity of the nuclear crisis at the Fukushima No. 1 power plant to the highest level under the international standard, putting it on a par with the 1986 Chernobyl catastrophe - the worst atomic power disaster in history.
The latest assessment, which raises the level from 5 to 7, highlights Tokyo's failure so far to defuse the nuclear crisis at the crippled Fukushima plant more than a month after the March 11 earthquake and tsunami, and forces the government to acknowledge it as one of the two worst nuclear disasters ever.
Still, Nuclear and Industrial Safety Agency spokesman Hidehiko Nishiyama attempted to play down the impact of the assessment, saying the severity of the Fukushima crisis is nowhere near that of Chernobyl, where huge amounts of radioactive materials were spewed into the environment.