Japan expands nuclear evacuation zone, new quake hits, Posted by Meosha Eaton

* High radiation forces extention of evacuations

* 7.1 magnitude quake triggers tsunami alert

* Voter anger at nuclear crisis hits PM Kan's party

* No end in sight to month-long nuclear crisis (Updates with strong quake and tsunami alert, evacuation details)

By Yoko Kubota and Yoko Nishikawa

TOKYO, April 11 (Reuters) - Japan on Monday expanded the evacuation zone around its crippled nuclear plant because of high levels of accumulated radiation, as a strong aftershock rattled the area one month after a quake and tsunami sparked the worst nuclear crisis since Chernobyl.

A magnitude 7.1 tremor shook buildings in Tokyo and a wide swathe of eastern Japan on Monday evening, triggering a small tsunami alert. NHK state television said it caused the off-site power supply for two damaged reactors to shut down.

The U.S. Geological Survey said the aftershock struck 38 km (24 miles) west of the city of Iwaki, at a depth of 13 km (8 miles).

Tokyo Electric Power Co (TEPCO) , which operates the plant, said workers had stopped pouring cooling water on reactors No. 1, No. 2 and No. 3 at Fukushima.

Chief Cabinet Secretary Yukio Edano said villages and towns outside the 20 km (12 mile) evacuation zone that have had more accumulated radiation would be evacuated. Children, pregnant women, and hospitalised patients should stay out of some areas 20-30 km from the Fukushima nuclear complex, he added.

The decision to widen the evacuation band around the Fukushima plant was "based on data analysis of accumulated radiation exposure information", Edano told a news conference.

"These new evacuation plans are meant to ensure safety against risks of living there for half a year or one year," he said. There was no need to evacuate immediately, he added.

Japan had resisted extending the zone despite international concerns over radiation spreading from the six damaged reactors at Fukushima, which engineers are still struggling to bring under control after they were wrecked by the 15-metre tsunami.

Residents of one village, Iitate, which is 40 km from the Fukushima Daiichi plant, have been told to prepare for evacuation because of prolonged exposure to radiation, a local official told Reuters by phone. It has a population of 5,000.

The International Atomic Energy Agency has urged Japan to extend the zone and some countries, including the United States, have advised their citizens to stay 80 km away from the plant.

TEPCO President Masataka Shimizu visited the area on Monday for the first time the March 11 disaster. He had all but vanished from public view apart from a brief apology shortly after the crisis began and has spent some of the time since in hospital.

"I would like to deeply apologise again for causing physical and psychological hardships to people of Fukushima prefecture and near the nuclear plant," said a grim-faced Shimizu.

Dressed in a blue work jacket, he bowed his head for a moment of silence with other TEPCO officials at 2:46 p.m. (0546 GMT), exactly a month after the earthquake hit.

Fukushima Governor Yuhei Sato refused to meet Shimizu during his visit, but the TEPCO boss left a business card at the government office.

Sato has criticised the evacuation policy, saying residents in a 20-30 km radius were initially told to stay indoors and then advised to evacuate voluntarily.

RADIOACTIVE WATER

Engineers at the damaged Daiichi plant north of Tokyo said they were no closer to restoring the plant's cooling system which is critical if overheated fuel rods are to be cooled and the six reactors brought under control.

In a desperate move to cool highly radioactive fuel rods, operator Tokyo Electric Power Co (TEPCO) <9501.t> has pumped water onto reactors, some of which have experienced partial meltdown.

But the strategy has hindered moves to restore the plant's internal cooling system, critical to end the crisis, as engineers have had to focus how to store 60,000 tonnes of contaminated water.

Engineers have been forced to pump low-level radioactive water, left by the tsunami, back into the sea in order to free up storage capacity for highly contaminated water from reactors.

China and South Korea have both criticised Japan for pumping radioactive water into the sea, with Seoul calling it incompetent, reflecting growing international unease over the month-long atomic disaster and the spread of radiation.

TEPCO hopes to stop pumping radioactive water into the ocean on Monday, days later than planned.

Engineers are also pumping nitrogen into reactors to counter a build-up of hydrogen and prevent another explosion sending more radiation into the air, but they say the risk of such a dramatic event has lowered significantly since March 11.

POLITICAL FALLOUT

The triple disaster is the worst to hit Japan since World War Two after a 9.0 magnitude earthquake and a huge tsunami battered its northeast coast, leaving nearly 28,000 dead or missing and rocking the world's third-largest economy.

Concern at Japan's inability contain its nuclear crisis is mounting with Prime Minister Kan's ruling party suffering embarrassing losses in local elections on Sunday.

Voters vented their anger at the government's handling of the nuclear and humanitarian crisis, with Kan's ruling Democratic Party of Japan losing nearly 70 seats in local elections. [ID:nL3E7FA09V]

The unpopular Kan was already under pressure to step down before March 11, but analysts say he is unlikely to be forced out during the crisis, set to drag on for months.

"The great disaster was a double tragedy for Japan. The first tragedy was the catastrophe caused by the earthquake, tsunami and the nuclear accident. The other misfortune was that the disaster resulted in prolonging Prime Minister Kan's time in office," Sankei newspaper said in an editorial on Monday. ($1=85.475 Japanese yen) (Additional reporting by Issei Kato, Shinichi Saoshiro, Chisa Fujioka, Elaine Lies, Masahiro Koike and Linda Sieg in Tokyo; Writing by Michael Perry; Editing by Jonathan Thatcher and Alex Richardson)

Japan stops nuclear plant leak; crisis far from over, Posted by Meosha Eaton

* Liquid glass seals ground, stops leaks

* Nuclear crisis far from under control

* Fisherman angry over contaminated water being pumped into sea

* Vast sea to dilute radioactive water - expert (Updates with cumulative radiation concerns, angry fishermen)

By Shinichi Saoshiro and Yoko Nishikawa

TOKYO, April 6 (Reuters) - Japan stopped highly radioactive water leaking into the sea on Wednesday from a crippled nuclear plant and acknowledged it could have given more information to neighbouring countries about contamination in the ocean.

Despite the breakthrough in plugging the leak at the Fukushima Daiichi power plant, engineers need to pump 11.5 million litres (11,500 tonnes) of contaminated water back into the ocean because they have run out of storage space at the facility. The water was used to cool over-heated fuel rods.

Nuclear experts said the damaged reactors were far from being under control almost a month after they were hit by a massive earthquake and tsunami on March 11.

Plant operator Tokyo Electric Power (TEPCO) said it had stemmed the leak using liquid glass at one of the plants six reactors.

"The leaks were slowed yesterday after we injected a mixture of liquid glass and a hardening agent and it has now stopped," a TEPCO spokesman told Reuters.

Engineers had been struggling to stop leaks from reactor No. 2, even using sawdust and newspapers.

Neighbours South Korea and China are getting concerned about the world's worst nuclear disaster since Chernobyl in 1986, and the radioactive water being pumped into the sea, newspapers reported.

"We are instructing the trade and foreign ministries to work better together so that detailed explanations are supplied especially to neighbouring countries," Chief Cabinet Secretary Yukio Edano told a news conference.


Experts insisted the low-level radioactive water to be pumped into the ocean posed no health hazard to people.

"The original amount of radioactivity is very low, and when you dilute this with a huge body of water, the final levels will be even lower than legal limits," said Pradip Deb, senior lecturer in Medical Radiations at the School of Medical Sciences, Royal Melbourne Institute of Technology University.

The government is preparing to revise guidelines for legal radiation levels, designed for brief exposure to high levels of radiation in emergencies and not cumulative absorption, for people living near the damaged plant.

Workers are struggling to restart cooling pumps -- which recycle the water -- in four damaged reactors.

Until those are fixed, they must pump in water to prevent overheating and meltdowns, but have run out of storage capacity for the seawater when it becomes contaminated.

Radioactive iodine detected in the sea has been recorded at 4,800 times the legal limit, but has since fallen to about 600 times the limit. The water remaining in the reactors has radiation five million times legal limits.

"What they are going to have to release is likely to be highly radioactive. The situation could politically be very ugly in a week," said Murray Jennex at San Diego State University, who specialises in nuclear containment.

Japan's fishermen, who are part of the politically powerful agriculatural lobby, made it clear they were not assuaged by assurances that ocean radioactivity levels were low and safe.

"(The release of radioactive water into the sea) is unforgivable in any circumstance," Ikuhiro Hattori, chairman of the Japan Fisheries Cooperatives, told NHK state television.

"From now on, our fishermen will never cooperate with or accept nuclear power generation. I would like them to stop even those reactors that are now in operation right away."


COOLING REACTORS KEY

Japan is facing its worst crisis since World War Two after the 9.0 magnitude earthquake and tsunami left nearly 28,000 people dead or missing and thousands homeless, and rocked the world's third-largest economy.

It will likely take months to finally cool down the reactors and years to dismantle those that have been damaged. TEPCO has said it will decommission four of the six reactors.

An opposition lawmaker from Fukushima told reporters antipathy in the area would make it difficult to resume operations at the nearby Fukushima Daini plant, where operations have been halted since March 11.

The two Fukushima plants together provide four percent of Japan's electric power. [ID:nTKB007431]

"Nuclear power plants can run only with local consent. I see it as being quite difficult to resume operations," said Masayoshi Yoshino of the Liberal Democratic Party.

Concerned over a possible buildup of hydrogen gas in reactor No. 1, engineers will inject nitrogen gas into the reactor on Wednesday night to prevent an explosion, TEPCO said.

Hydrogen explosions ripped through reactors 1 and 3 early in the crisis, spreading high levels of radiation into the air.

The key to bringing the reactors under control is the extent of damage to the plant's cooling system, said analysts.

In a sign the cooling systems may be severely damaged, the Sankei newspaper reported that the government and TEPCO were considering building new cooling systems for three reactors to operate from outside the reactor buildings.

"To put the Fukushima nuclear catastrophe in perspective, Chernobyl involved a single operating reactor core," said Kevin Kamps from Beyond Nuclear, a U.S. radioactive waste watchdog.

"Fukushima Daiichi now involves three reactors in various stages of meltdown and containment breach, and multiple (spent fuel storage) pools at risk of fire," said Kamps.

Kamps said the spent fuel rod pools, which are on the roof of the damaged reactors, alone have more irradiated nuclear fuel than that which exploded and burned at Chernobyl. ($1=84 Japanese yen) (Additional reporting by Kiyoshi Takenaka in Tokyo, Scott DiSavino in New York and Tan Ee Lyn in Singapore; Writing by Michael Perry and Paul Eckert; Editing by Jonathan Thatcher and Robert Birsel)