WRAPUP 6-Radioactivity soars inside Japanese reactor, workers evacuated

* Radioactivity soars in reactor 2, workers evacuated

* Crisis far from end, says U.N. nuclear chief

* More than 10,480 dead, 16,600 missing after quake, tsunami

(Updates throughout)

By Shinichi Saoshiro and Taiga Uranaka

TOKYO, March 27 (Reuters) – Japanese authorities evacuated
workers on Sunday from a reactor building they were working in
after radiation in water at the crippled nuclear power plant
reached potentially lethal levels, the plant’s operator said.

Tokyo Electric Power Co said radiation in the water
of the No. 2 reactor at the Fukushima Daiichi plant was measured
at more than 1,000 millisieverts an hour. That compares with a
national safety standard of 250 millisieverts over a year. The
U.S. Environmental Protection Agency says a dose of 1,000
millisieverts is enough to cause haemorrhaging.

Japanese nuclear regulators said the water contained 10
million times the amount of radioactive iodine than is normal in
the reactor, but noted the substance had a half life of less
than an hour, meaning it would disappear within a day.

A Tokyo Electric official said workers were evacuated from
the No. 2 reactor’s turbine housing unit to prevent them from
being exposed to harmful doses of radiation. They had been
trying to pump radioactive water out of the power station after
it was found in buildings housing three of the six reactors.

Tokyo Electric engineers have struggled the past two weeks
to prevent a catastrophic meltdown at Fukushima Daiichi, after
an unprecedented earthquake and tsunami knocked out the backup
power system needed to cool the reactors.

The work has had to be suspended several times due to
explosions and spiking radiation levels inside the reactors, in
a crisis that has become the worst nuclear emergency since
Chernobyl a quarter-century ago.

On Thursday, three workers were taken to hospital from
reactor No. 3 after stepping in water with radiation levels
10,000 times higher than usually found in a reactor.

The latest radiation scare was confined to inside the
reactor. Radiation levels in the air beyond the evacuation zone
around the plant and in Tokyo have been in normal ranges.

Yukiya Amano, the director general of the International
Atomic Energy Agency (IAEA), cautioned that the nuclear
emergency could go on for weeks, if not months more.

“This is a very serious accident by all standards,” he told
the New York Times. “And it is not yet over.”

Radiation levels in the sea off the Fukushima Daiichi plant
rose on Sunday to 1,850 times normal just over two weeks after
the disaster struck, from 1,250 on Saturday, Japan’s Nuclear and
Industrial Safety Agency said.

“Ocean currents will disperse radiation particles and so it
will be very diluted by the time it gets consumed by fish and
seaweed,” said Hidehiko Nishiyama, a senior agency official.

Several countries have banned produce and milk from Japan’s
nuclear crisis zone and are monitoring Japanese seafood over
fears of radioactive contamination.

OVERSHADOWING RELIEF EFFORT

The crisis at the plant, 240 km (150 miles) north of Tokyo,
has overshadowed a relief and recovery effort from the magnitude
9.0 quake and the huge tsunami it triggered on March 11 that
left more than 27,100 people dead or missing in northeast Japan.

The Japanese government estimated last week the material
damage from the catastrophe could top $300 billion, making it
the world’s costliest natural disaster.

In addition, power cuts have disrupted production while the
drawn-out battle to prevent a meltdown at the 40-year-old plant
has hurt consumer confidence and spread contamination fears well
beyond Japan.

Amano, a former Japanese diplomat who made a trip to Japan
after the quake, said authorities were still unsure about
whether the plant’s reactor cores and spent fuel were covered
with the water needed to cool them.

He told the newspaper he saw a few “positive signs” with the
restoration of some electric power to the plant, adding: “More
efforts should be done to put an end to the accident.”

U.N. Secretary-General Ban Ki-moon said it was time to
reassess the international atomic safety regime.

Japan’s nuclear crisis also looks set to claim its first, and
unlikely, political casualty. In far away Germany, Chancellor
Angela Merkel’s party faces a defeat in a key state on Sunday,
largely because of her policy U-turns on nuclear
power.

NOT WORSENING

A Tokyo Electric official told a news conference on Saturday
experts were still trying to figure out where to put the
contaminated water they’re trying to pump out of the reactors.

They also are not sure where the radiation is leaking from
— whether its from the spent fuel rod pools or elsewhere in the
reactors.

“That’s the problem they have right now, is trying to figure
out where this comes from,” said Murray Jennex, associate
professor at San Diego State University.

“You let (radioactive)stuff accumulate because you don’t
have a place to put it. It stays down in the bottom of the
plant. If nothing happens, when it comes time to shut it down
you clean it up and take care of it. But if something like this
happens, that stuff now becomes loose sometimes.”

Two of the Fukushima Daiichi reactors are now seen as safe
but the other four are volatile, occasionally emitting steam and
smoke.

“We are preventing the situation from worsening,” Chief
Cabinet Secretary Yukio Edano told a news conference on
Saturday. “We’ve restored power and pumped in fresh water, and
are making basic steps towards improvement, but there is still
no room for complacency.”

At Chernobyl in Ukraine, the worst nuclear accident in the
world, it took weeks to “stabilise” what remained of the reactor
that exploded and months to clean up radioactive materials and
cover the site with a concrete and steel sarcophagus.

In Tokyo, a metropolis of 13 million, a Reuters reading on
Sunday morning showed ambient radiation of 0.06 microsieverts
per hour, well within the global average of naturally occurring
background radiation of 0.17-0.39 microsieverts per hour, a
range given by the World Nuclear Association.

(Additional reporting by Kiyoshi Takenaka, Chizu Nomiyama,
Shinichi Saoshiro and Phil Smith in Tokyo, Jon Herskovitz in
Kamaishi; writing by Bill Tarrant; editing by)

WRAPUP 6-Radioactivity soars inside Japanese reactor, workers evacuated