Japan is to raise its assessment of the severity of its nuclear emergency to the maximum seven on an international scale, putting it on a par with Chernobyl, reports said Tuesday.

 

Military fire trucks sprayed the reactor units with water to prevent the fuel from overheating and emitting dangerous levels of radiation. (AP Photo/Japan Defense Ministry)

 The government currently rates the incident at five, but will boost that to seven, Kyodo and NHK said, citing unnamed sources, classifying it as a major incident.

 The Fukushima Daiichi nuclear plant was badly damaged by the March 11 earthquake and tsunami that hit Japan and has been leaking radiation since, despite efforts to cool and stabilise its reactors.

 Kyodo earlier reported that preliminary figures from the country's Nuclear Safety Commission revealed the battered plant had released 10,000 terabecquerels of radioactive material per hour for several hours.

 That calculation prompted Japan to consider upgrading the accident to the highest level -- something that has only been given to the 1986 Chernobyl disaster -- Kyodo said, citing unnamed government sources.

 According to the International Nuclear Events Scale, level seven incidents are ones with a "major release of radioactive material with widespread health and environmental effects requiring implementation of planned and extended countermeasures."

 Haruki Madarame, chairman of the government-run commission, said it has estimated that the release of 10,000 terabecquerels of radioactive materials per hour continued for several hours, the report said.

 Japan currently assesses the nuclear accident at level 5, or the same level as the Three Mile Island accident in the United States in 1979.

 On Monday the disaster-stricken nation marked a month since the massive earthquake and tsunami hit northeastern Japan.

 -AFP/ac