New quake reported off Honshu

TOKYO, April 14 (UPI) -- Japan's quake-ruined Honshu Island was hit by a 6.1-magnitude offshore temblor Thursday, the U.S. Geological Survey said.

As workers battled the nuclear crisis at the Fukushima Daiichi plant on the island while facing unrelenting aftershocks, the latest of those shocks off the east coast, 333 miles northeast of Tokyo, struck at 5:57 a.m., the U.S. Geological Survey said, but there were no immediate reports of damage locally or at the Fukushima nuclear plant.

No tsunami warning was issued.

The severity of the of the nuclear crisis at the Fukushima plant, 140 miles north of Tokyo, was raised this week from level 5 to the maximum level 7, bringing it on par with the world's worst nuclear disaster, which hit the Chernobyl plant in Ukraine in 1986. However, Japanese officials have said the Fukushima plant's radioactive emissions are only about the 10 percent of what resulted from Chernobyl.

It was a horrific tsunami on the heels of a 9-magnitude earthquake on March 11 that crippled the six-reactor plant, setting off one of the world's worst nuclear crises, killing and leaving missing tens of thousands of people and inflicting economic damage already running into the hundreds of billions of dollars on a country that was beginning to enjoy a recovery after years of crippling deflation.

Fukushima plant operator Tokyo Electric Power confirmed Wednesday some of the 1,331 stored spent nuclear fuel rods in the No. 4 reactor building had been damaged but most of those rods were believed to be in sound condition, Kyodo News reported.

That confirmation came after the utility's analysis of water from the reactor's spent nuclear fuel pool showed higher levels of radioactive iodine-131, cesium-134 and cesium-137. The No. 4 reactor had been idled prior to March 11 for regular inspection which required storing both its spent and new fuel rods in its pool but the quake and tsunami may have caused the fuel to overheat, thus damaging the rods which in turn raised the levels of the radioactive materials cause by nuclear fission.

The No. 4 reactor building lost its roof and some of the upper walls in a hydrogen explosion and fires resulting in the March 11 incident. Explosions also badly damaged the No. 1, 2 and 3 reactors at the time.

Earlier, Tokyo Electric had estimated 25 percent to 70 percent of the nuclear fuel rods in the Nos. 1, 2 and 3 reactors may have been damaged.

The utility said the damage to the fuel rods may also have resulted from steel frames falling into the pool already without its cooling function. It planned to deploy a small unmanned helicopter to see if the damaged rods can be extracted.

The urgent task for the workers at the moment is to remove highly radioactive water collecting in the basements of the reactors.

Kyodo News said workers have pumped out 700 tons of the estimated 60,000 tons of the highly contaminated water from an underground trench into a condenser. Once all the contaminated water is removed, which may take weeks, the next task would be to store it tanks.

In other developments, the healthy ministry said radioactive cesium 25 times over the legal limit was found Wednesday in young sand lance fish off Fukushima prefecture, Kyodo News reported.

In an interview to Kyodo News, the vice-chairman of the Japan Atomic Energy Commission, urged a thorough investigation of the nuclear crisis by an independent panel that could include outside experts to ensure openness and transparency that can be verified by the international community.

CNN reported the president of Tokyo Electric has announced efforts with the government to provide short-term compensation to those affected by the nuclear crisis. His comments came after Japanese Prime Minister Naoto Kan assured to bring an end to the nuclear crisis at all costs.

The latest confirmed death toll from the March 11 disaster exceeded 13,300. Those missing exceeded 15,000 people.