(Adds quotes, reading measurements)
By Tetsushi Kajimoto
TOKYO, Sept 1 Radiation near a tank holding
highly contaminated water at Japan's crippled Fukushima nuclear
plant has spiked 18-fold, the plant's operator said on Sunday,
highlighting the struggle to bring the crisis under control
after more than two years.
Radiation of 1,800 millisieverts per hour - enough to kill
an exposed person in four hours - was detected near the bottom
of one storage tank on Saturday, Tokyo Electric Power Co
, also known as Tepco, said.
An Aug. 22 readings measured radiation of 100 millisieverts
per hour at the same tank. Japanese law has set an annual
radiation exposure safety threshold of 50 millisieverts for
nuclear plant workers during normal hours.
Last month, Tepco revealed that water from the tank was
leaking. Japan's nuclear regulator later raised the severity of
the leak from a level 1 "anomaly" to a level 3 "serious
incident" on an international scale for radiation releases.
The Fukushima Daiichi power plant north of Tokyo was
devastated by a tsunami on March 11, 2011 that resulted in
fuel-rod meltdowns at three reactors, radioactive contamination
of the air, sea and food and the evacuation of 160,000 people.
It sparked the worst nuclear crisis since Chernobyl a
quarter of a century earlier.
While there were no new leaks found at the tank, a Tepco
spokesman said another leak had been detected from a pipe
connecting two other tanks nearby.
"We have not confirmed fresh leakage from the tank and water
levels inside the tank has not changed," the Tepco spokesman
said. "We are investigating the cause."
Tepco said the radiation measured was beta rays, which would
be easier to protect against than gamma rays.
The Tepco spokesman also said the higher level of radiation
from the latest reading was partly because investigators had
used a measuring instrument capable of registering greater
amounts of radiation.
Instruments used previously had only been capable of
measuring radiation up to 100 millisieverts, but the new
instruments were able to measure up to 10,000 millisieverts.
Radiation of 220 millisieverts was also recorded near an
adjacent storage tank, where a reading of 70 had been registered
Radiation of 230 millisieverts was detected from the new
leak from the pipe connecting two nearby tanks, a new
measurement of 70 was taken from another, separate storage tank.
Those tanks are built of steel plates stuck together by
bolts - the same structure as the tank that was found last month
to have leaked 300 tonnes of highly toxic water.
With no one seeming to know how to bring the crisis to an
end, Tepco said last week it would invite foreign
decommissioning experts to advise it on how to deal with the
highly radioactive water leaking from the site.
Japan has also signalled it might dip into a $3.6 billion
emergency reserve fund to help pay for the clean-up of a
situation the chief cabinet secretary has described as
Its nuclear regulator has also expressed fear that the
disaster was beyond Tepco's ability to cope in some respects.
Foreign Minister Fumio Kishida visited Chernobyl in Ukraine,
the site of the 1986 disaster, hoping to apply lessons learned
there to Fukushima.
(Editing by Paul Tait)