(Refiles to fix title of an official in paragraph 17)
* Japan seeks Russian radiation treatment ship
* Operators forced to release radioactive water into sea
* Bath salts, sea curtain sought to stop radiation leaks
* Nuclear crisis may weaken yen, economy to be hit
(Updates amount of contaminated water to be discharged)
By Chizu Nomiyama and Shinichi Saoshiro
TOKYO, April 5 Japan has asked nuclear
superpower Russia to send a special radiation treatment ship
used to decommission nuclear submarines as it fights to contain
the world's worst atomic crisis since Chernobyl, Japanese media
said late on Monday.
Japanese engineers at the Fukushima Daiichi nuclear plant
have been forced to release radioactive waste water into the
sea. At the same time they are resorting to desperate measures
to contain the damage, such as using bath salts to try to locate
the source of leaks at the crippled complex 240 km (150 miles)
north of Tokyo.
Three weeks after a 9.0 magnitude earthquake and massive
tsunami hit northeast Japan, sending some of Daiichi's reactors
into partial meltdown, engineers are no closer to regaining
control of the power plant or stopping radioactive leaks.
The quake and tsunami left nearly 28,000 people dead or
missing and Japan's northeast coast a wreck.
The world's costliest natural disaster has caused power
blackouts and cuts to supply chains and business hours. It is
threatening economic growth and the yen, while a recent opinion
poll suggested voters want embattled Prime Minister Naoto Kan to
form a coalition in order to steer Japan through its worst
crisis since World War Two.
Plant operator Tokyo Electric Power Co (TEPCO) was
forced on Monday to release low-level radioactive seawater that
had been used to cool overheated fuel rods after it ran out of
storage capacity for more highly contaminated water.
A TEPCO official was in tears as he told a news conference:
"We are very sorry for this region and those involved."
The water, which is being released to free storage capacity
for more highly contaminated water, is about 100 times more
radioactive than legal limits. Koichi Nakamura, a deputy
director-general of Japan's Nuclear Industrial Safety Agency
(NISA), told a news conference in Vienna about 11,500 tonnes of
water would have to be discharged.
He also said Japan had not ruled out expanding the 20-km
evacuation zone around the site. [ID:nLDE73326Z]
Engineers planned to build two giant "silt curtains" made of
polyester fabric in the sea to hinder the spread of more
contamination from the plant.
Japan has also asked Russia for the "Suzuran", a ship which
treats radioactive liquids, Kyodo and Jiji news agencies said.
The ship, a joint venture between Japan and Russia, was
designed to help decommission nuclear submarines in Russia's
Pacific fleet in Vladivostock, ensuring radioactive waste was
not dumped into the Sea of Japan, Kyodo said.
It could take months to stem the leaks and longer to regain
control of the power station, damaged by the March quake and
tsunami, though a U.S. official in Vienna said there was no
evidence the spent fuel in the reactors was restarting a nuclear
reaction after being shut down.
DISASTER MAY SEE YEN WEAKEN
Japan, the world's third largest economy but also one of its
most indebted nations, has estimated the damages bill may top
"The damage from the nuclear crisis and the subsequent power
shortage will last for several years," said Eiji Hirano, former
assistant governor of the Bank of Japan (BOJ).
"There's a strong chance Japan's economy will contract in
the current fiscal year," he told Reuters in an interview.
A former senior finance ministry official, Eisuke
Sakakibara, said the yen would weaken in the coming months,
possibly beyond 90 to the dollar, underlining expectations a
near four-year rally in the currency may be over.
The yen traded at 84.05 per dollar early on Tuesday.
The disaster initially saw the yen soar on speculation
Japanese would repatriate funds for reconstruction, prompting
the G7 intervention to knock it back.
"This atomic power issue is an incident which would result
in depreciation of the exchange rate," Sakakibara told reporters
Unpopular and under pressure to quit or call a snap poll
before the disaster, Prime Minister Kan has been criticised for
his management of the disaster.
One newspaper poll said nearly two-thirds of voters wanted
the government to form a coalition with the major opposition
party and work together to recover from the disaster.
BATH SALTS, SEA CURTAIN
In their desperation to stop radioactive leaks, TEPCO
engineers have used anything at hand. They have mixed sawdust
and newspapers with polymers and cement in an unsuccessful
attempt to seal a crack in a concrete pit at reactor No.2.
On Monday, they resorted to powdered bath salts to produce a
milky colour in water to help trace the source of the leak.
TEPCO said it was also planning to drape a curtain into the
sea off the nuclear plant to try to prevent radioactive silt
drifting out into the ocean.
The exact source of the radiation leaks remains unknown.
NISA is investigating a damaged embankment near a sluice gate at
the No.2 reactor and the possibility it may be seeping through a
layer of small stones below a concrete pipe.
TEPCO said it would build tanks to hold contaminated
seawater, was towing a floating tank which will arrive next
week, and was negotiating the purchase of three more.
"If the current situation continues for a long time,
accumulating more radioactive substances, it will have a huge
impact on the ocean," Chief Cabinet Secretary Yukio Edano said.
Small levels of radiation from the plant have been detected
as far away as Europe and the United States and several
countries have banned milk and produce from the vicinity.
Singapore extended a ban on Japanese food imports on Monday
after detecting radiation in more fruit and vegetable imports.
Kan asked the European Union on Monday for a calm response to
Japanese imports. The EU has urged radiation testing of Japanese
food and feed imports.
(Additional reporting by Yoko Nishikawa, Yoko Kubota, Linda
Sieg, Leika Kihara, Tetsushi Kajimoto in Tokyo and Sylvia
Westall in Vienna; Writing by Michael Perry; Editing by Daniel