Japan?s nuclear plant disaster?s severity level revised upward

As threat from the tsunami-stricken Fukushima Daiichi nuclear plant continues to loom large, Japan?s nuclear regulators on Tuesday raised the severity level of the crisis to 7 ? the highest level on an international scale overseen by the International Atomic Energy Agency.

This puts the disaster at par with the 1986 Chernobyl disaster.

The high level of radioactive particles released into the atmosphere since the incident has led to the revision of the severity level from 5 to 7.

This puts in it in the category of a “major accident” with “wider consequences”.

?We have upgraded the severity level to 7 as the impact of radiation leaks has been widespread from the air, vegetables, tap water and the ocean,? Japan’s Nuclear and Industrial Safety Agency (NISA) official said.

The revision was based on cross-checking and assessments of data on leaks of radioactive iodine-131 and cesium-137.

The NISA official pointed that there have been no explosions of reactor cores at the Fukushima Daiichi plant, although there were hydrogen explosions, unlike the Chernobyl disaster.

The amount of radiation leaking from the Fukushima Daiichi nuclear plant was around 10 percent of the Chernobyl accident.

In Chernobyl, in the Ukraine, a reactor exploded on April 26, 1986, spewing a cloud of radiation over much of the Northern Hemisphere.

A zone about 19 miles (30 kilometers) around the plant was declared uninhabitable, although some plant workers still live there for short periods and a few hundred other people have returned despite government encouragement to stay away.

Earlier on Monday, Japan had expanded the evacuation zone around the crippled nuclear plant because of high levels of radiation as strong earthquake shocks struck off the country?s northeast coast, killing one person and triggering a tsunami warning.

The first quake had a magnitude of 6.6 and caused a temporary loss of external power at the Fukushima Daiichi atomic power station. According to local television reports, elsewhere in the Fukushima prefecture, several cars with passengers were engulfed in a landslide.

Twenty-five aftershocks followed the quake, centred 88 km west if the crippled Fukushima power station and power supplies to 220,000 households were knocked out as building swayed in Tokyo and other parts of eastern Japan.

Japan is already reeling from the 9.0 earthquake, the biggest in the quake-prone country?s recorded history, that struck on Mar 11 triggering a 10-metre high tsunami and a major nuclear crisis, causing millions of dollars in damages and leaving about 28,000 people dead or missing.

Meanwhile, Tokyo Electric Power Co (TEPCO), the operator of the plant, said it had completed its controlled discharge of radiated sea-water some of which was used to cool reactors after their cooling systems failed and the rest brought in by the tsunami.

The company had said it had pumped out 10,400 tonnes of low-level radioactive water, amid contamination concerns raised by China and South Korea. Authorities also said that children, pregnant women, and hospitalised patients should avoid a radius of 20-30 km from the atomic station.