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)

New U.S. air rules may benefit nuclear energy, Posted by Meosha Eaton

* EPA rules could ensure reliance on nuclear

* Rules could shut aging coal plants

WASHINGTON, March 16 (Reuters) - U.S. environmental regulators will propose pollution rules on Wednesday that could ensure continued reliance on nuclear power by forcing aging coal plants into early retirement.

The Environmental Protection Agency said it will unveil standards on mercury, which can damage nervous systems in babies, and other airborne toxins from power plants at 1100 EDT (1500 GMT).

Japan's battle to stop earthquake-damaged nuclear reactors from melting down has pushed some countries to be more cautious on atomic energy. Germany, which has taken the strongest stance after the disaster, plans to shut seven of its older nuclear plants, or a quarter of its atomic energy, for a three-month safety review.

The United States has said it remains committed to the technology. U.S. Energy Secretary Steven Chu said on Wednesday that federal regulators will look to boost the safety of the nation's nuclear plants after the Japan crisis.

Coal-fired plants generate nearly 50 percent of U.S. electricity while nuclear and natural gas generate about 20 percent each.

The EPA crackdown could help shut some 15 to 20 percent of aging U.S. coal-fired plants.

That could increase reliance on natural-gas-fired power plants, which can be built quickly and pollute less than traditional coal-fired power plants.

It could also ensure that the country continues to derive large amounts of power from nuclear plants, despite the Japanese crisis, because they emit virtually no gases. (Editing by Jim Marshall)

Q+A: What do latest events at Japan nuclear power plant mean? Posted by Meosha Eaton

By Elaine Lies

March 16 (Reuters) - Japan's nuclear crisis worsened on Wednesday, with workers ordered to withdraw briefly from the stricken power plant after radiation levels spiked, just hours after smoke was seen rising from the quake-crippled nuclear facility.


Q: What does the smoke mean?

A: The smoke is most likely to be steam, a natural byproduct of pouring water into the reactors to cool them down and keep the fuel rods covered. Authorities are also trying to maintain water levels at a spent-fuel storage pool at the plant's No. 4 reactor, which experts now view as the real threat.

The steam is an issue because it contains radioactive particles, but experts say these particles may not be as serious as, say, an explosion within a reactor core. So far, it appears the radiation is mostly escaping in the form of steam and some experts believe the radioactive particles could merely be dust or from rusted structures within the reactor buildings -- known as "crud" within the nuclear industry. Radiation levels have not risen significantly in Tokyo, about 240 km to the south.


Q: Why is the situation at the spent-fuel pool a worry?

A: Unlike the reactors themselves, which are inside two containers -- a massive steel container as well as one made of concrete -- the fuel pools are not, with meters of water on top of the rods providing safety only under normal circumstances. Another concern with reactor No. 4 is that the water levels in the pool could be falling, perhaps because the water is or has been boiling and is evaporating as steam.

While nobody knows exactly how much damage Tuesday's explosion did to the building, the structure does have holes and some experts have said that proposals to drop boric acid particles on the reactor suggest substantial holes in the roof.

"That's got to be protected. I'd hate to see another explosion there," said Murray Jennex, a professor at San Diego State University in California.


Q: What can be done?

A: Dropping boric acid could be helpful since it is both a fire suppressant and also absorbs radiation, while keeping water levels up in the pool is also essential. Finally, a fresh crew of workers should be sent into the plant since those who are in there are likely exhausted and may be making poor decisions, which could be adding to problems.


Q: What about the spent-fuel pools at the other reactors?

A: There are six reactors at the Daiichi complex. Three of them - no. 4 through No.6 - were offline for maintenance at the time of the quake. There are signs that water temperatures are also rising at No.5 and No.6 spent-fuel pools.

But the spent fuel at these two pools, as well as at the three reactors that were online at the time of the quake, is all older and thus less likely to pose an overheating threat.


Q: What about the other reactors?

A: There have been explosions at reactors No.1, No.2 and No.3, and suspicions that the suppression pool at No. 2 may have been damaged. But experts say that current low radiation levels suggest that the container vessels at these reactors are by and large holding, and that they're actually more optimistic about this situation than they were on Tuesday.

Doubt does remain about possible damage to the suppression pool at No. 2, but these are "overdesigned" to cope with a certain amount of damage.


Q: What do we need to watch out for?

A: Steadily rising radiation levels are the main worry, along with a fall in the water level in the spent fuel pool. Radiation levels at the plant's main gate spiked on Wednesday morning but have since fallen back, which is a good sign.

"If we have the water level doing down and rising radiation, that's a bad sign, because this means more and more of this fuel (is) exposed," said Najm Meshati, professor of civil and environmental engineering, at the University of Southern California at Los Angeles.

(Editing by Mark Bendeich

Oil slides after quake, tsunami slam Japan, Posted by Meosha Eaton

* U.S. crude below $100
* Earthquake Japan's largest in 140 years
* Some refineries, nuclear power plants, manufacturers shut

(Updates prices)
By Ikuko Kurahone

LONDON, March 11 (Reuters) - Oil slid by on Friday, with U.S. crude falling below $100, after an earthquake rocked Japan, created a 10-metre tsunami and shut down dozens of plants in the world's third-largest oil consumer. The oil market was also keeping an eye on a planned day of demonstrations in Saudi Arabia, the world's top oil exporter, and violence in Libya, which has disrupted its oil exports.

U.S. crude fell to as low as $99.01 a barrel and was trading at $100.44 a by 1544 GMT. ICE Brent crude fell $1.40 to $114.07 a barrel. It has fallen from a 2-1/2-year high of $119.79 on Feb. 24. Metals and soft commodities also fell.

Japan was hit by a magnitude 8.9 earthquake, the largest since observations began in the late 19th century. About 200-300 bodies were found, said police in Miyagi, northern Japan, where the quakes and the tsunami hit the hardest. The death toll was expected to rise.

"We need to think what the potential impact on Japanese economy from the quake will be and what the impact on global economy will be," Olivier Jakob with Petromatrix said. "That may weigh on oil demand from Japan and the oil price." Japan is the third-largest energy consumer after China and the United States and imports almost all its energy needs.

Some refineries and nuclear power plants were shut, and analysts pointed out the shutdowns might increase demand for imports of refined products and fuels for electricity generators.

"Short-term the disruption in activity will be clearly negative for Japanese oil demand, but you may find that post the initial impact of the tsunami, there will be a need to deliver oil products to meet demand if you suffer losses in refinery output," said Harry Tchilinguirian, BNP Paribas' head of commodity markets strategy.

The earthquake triggered a 10-metre tsunami that swept away everything in its path, including houses, cars, ships and farm buildings, and then spread across the Pacific.
The Japanese government declared an emergency at nuclear power plants and evacuated thousands of residents. No radiation leak had been reported so far.
Jakob and Tchilinguirian also pointed out the potential for increased demand for natural gas and fuel oil from power producers to compensate for shutdowns of nuclear capacity.


MIDDLE EAST PROTESTS
In the Middle East, police flooded the streets of Saudi Arabia's capital to deter a planned day of demonstrations, while a small Shi'ite demonstrated was reported in Hofuf, in the oil-producing east.

In Libya, forces loyal to Libyan leader Muammar Gaddafi entered the oil port of Ras Lanuf in the east of the country and were fighting for control of the town, rebels said on Friday. "Looking further forward it would be optimistic to expect Libyan oil production to return to normal levels this year," Lawrence Eagles with J.P. Morgan said in a research note.

Elsewhere in the region, Bahraini police blocked several thousand protestors from reaching the royal palace. In Yemen, tens of thousands of protestors marched in the capital, and protests turned violent in the southern port city of Aden. Kuwaiti riot police fired tear gas to break up a small, peaceful demonstration by stateless Arabs demanding greater rights.

European shares fell to a three-month low after the quake in Japan and on growing unrest in the Arab world. U.S. retail sales rose 1 percent, the largest gain since October. But it did not reverse the fall in oil prices.

(Reporting by Ikuko Kurahone, additional reporting by Alejandro Barbajosa in Singapore; editing by James Jukwey and Jane Baird)