Japan using gas to avoid explosion at nuclear plant

TOKYO - WORKERS at Japan's stricken nuclear plant on Thursday pumped nitrogen gas into a crippled reactor in a bid to contain the world's worst atomic accident for 25 years and prevent a possible explosion.

With the crisis at the Fukushima Daiichi plant approaching its fourth week, operator Tokyo Electric Power said it was concerned a build-up of hydrogen gas at the No. 1 reactor could cause another explosion at the site.

The fresh challenge underscored the fragility of the situation at the stricken plant, after rare progress was seen on Wednesday when workers plugged a hole spewing highly radioactive water into the ocean. Tepco officials say hydrogen building up in the housing around reactor No. 1 could mix with incoming oxygen, creating an explosion.

Experts say the risk of a detonation could rise as the nuclear fuel rods cool and as the steam inside the containment vessel condenses into water, reducing pressure inside the unit and drawing air in through cracks.

The move came as an assessment by the US Nuclear Regulatory Commission dated March 26 emerged, citing persistent and growing threats at the plant, including the risk of gas build up and explosions. 

Workers began pumping in nitrogen, an inert gas abundant in the atmosphere, which they hope will displace the oxygen. The process to inject 6,000 cubic metres will take around six days, Tepco said.

Since the pressure level went up, they confirmed that the gas was successfully going into the container,' said a spokesman with Japan's nuclear safety agency. Tepco said it was also planning to inject nitrogen gas into reactors number 2 and 3 as a protective measure. 

-- AFP

Disasters put stress on children in Japan

Twenty-two-year-old mother Yoko Kamata sits with her baby Yuzuyu (left) and son Seiga (right) at a shelter in Kamaishi city in Iwate prefecture. -- PHOTO: AFP

KARAKUWA (Japan) - ZOOM in for a snapshot of apparent normalcy: children sitting in a circle, clasping playing cards tightly in their hands. They laugh, chat and occasionally hop up to break into a goofy dance.

Zoom out and the picture changes: The children are kneeling on mattresses in a chilly classroom they now call home. An elderly woman cries nearby, wondering whether her mother was killed by Japan's tsunami. Outside the school, a teacher fiddles with a radiation detector, checking to ensure the levels aren't high enough to make them sick - or worse.

Behind the smiling faces of thousands of children in shelters across this wave-battered wasteland, experts say there is often serious anxiety as everything these youngsters once held as normal is suddenly anything but.

'That's what is so wonderfully adaptive about children. They can move very easily into playing or laughing,' says psychologist Susie Burke, a disaster response specialist with the Australian Psychological Society. 'But that's not saying they're not deeply distressed and upset about what's going on.'

Reminders of the tiniest victims are scattered throughout the wreckage: a little girl's white shoe caked in mud, a red rubber ball coated in dust, a sodden comic book whose ink has run.

As many as 25,000 people may have been killed in the March 11 earthquake and tsunami that devastated Japan's north-east coast and damaged a nuclear plant, sending radiation spewing into the environment. Tens of thousands are still living in shelters. -- AP

Two tsunami victims found at Japan nuclear plant

Tepco said in a statement: 'We extremely regret losing the two young employees who tried to secure the safety of the plant while it was being hit by the quake and tsunami.' -- PHOTO: AP

TOKYO - THE bodies of two workers killed when a tsunami hit Japan's Fukushima nuclear plant more than three weeks ago have been found and recovered, operator Tokyo Electric Power Co (Tepco) said on Sunday.

A Tepco official cited physicians as saying Mr Kazuhiko Kokubo, 24, and Mr Yoshiki Terashima, 21 had died of bleeding from multiple injuries.

The utility said their remains had been found last Wednesday in the reactor four turbine building of the Fukushima plant, where the tsunami knocked out cooling systems and sparked an emergency that has released high radiation.

Their bodies required decontamination from radioactive materials, and they were only formally declared as deceased on Saturday, it said.

Tepco said in a statement: 'We extremely regret losing the two young employees who tried to secure the safety of the plant while it was being hit by the quake and tsunami.'

The crippled plant is continuing to release radiation into the air, ground and sea in Japan's worst ever nuclear crisis. -- AFP

Radiation worries hit Japan's farmers hard

FUKUSHIMA CITY (Japan) - ON HIS farm on the rural outskirts of Fukushima City, 73-year-old Akio Abiko digs up burdock roots and worries about the future.

For now, he is donating the roots to a nearby evacuee centre, to garnish rice and help feed those who have fled from the crippled Daiichi nuclear plant about 70km away.

But Mr Abiko and other local farmers wonder if anyone outside this part of north-east Japan will ever again want to buy produce from Fukushima. Mr Abiko used to sell carrots, potatoes and other vegetables from his 9,900 square metre farm to Tokyo. But the chances of that now look unlikely.

'Grown in Fukushima' has become a warning label for those nervous of radiation which has already been found in some vegetables close to the nuclear plant savaged by last month's earthquake and tsunami.

'There is no way we will be able to sell anything,' he said. 'People in Tokyo are just too sensitive about this kind of thing.' A group of farmers came to Tokyo from Fukushima at the weekend, using Geiger counters to show their produce was safe.

Japan's worst crisis since World War II, with the authorities still trying to bring the damaged reactors under control, has sparked widespread fears about the safety of its food. The radiation worries are likely to put a further squeeze on farmers in north-east Japan, where the economy has been on a steady decline for years, hit by a falling birthrate and a rapidly ageing population. -- REUTERS

Giant pumps rushed from US to Japan

WASHINGTON - TWO of the world's largest cement boom pumps are being rushed to Japan to help cool reactors at the crippled Fukushima Daiichi nuclear plant, the company that makes the equipment said on Friday.

Two giant trucks equipped with powerful pumps and flexible arms with a 70m reach will be used to shoot water from giant hoses to cool the nuclear reactors, or cement to seal off the site, said Ms Kelly Blickle, a spokesman with the US subsidiary of the German company Putzmeister.

Similar pumps were used in Chernobyl following the April 1986 meltdown, Ms Blickle told AFP. The boom pumps, normally used to pour concrete for bridges and skyscrapers under construction, can feed water over the destroyed buildings and target the reactor hotspots.

Tokyo Electric Power Co (Tepco), the Fukushima plant operator, 'didn't specifically say that they wanted to pump concrete, but it is the option, they don't have to bring in more equipment should that need occur', Ms Blickle said.

The equipment can also be operated via radio remote control - an operator can be some 2km away while maneuvering the boom pump. The company is working on extending that distance to 4km, Ms Blickle said.

Eleven Putzmeister truck-mounted concrete pumps and stationary pumps were used during the Chernobyl accident, the company said. Two US companies had bought the boom pumps, but agreed instead to let Putzmeister re-direct the machines to Japan and delay their orders, Ms Blickle said. -- AFP

Hundreds of bodies in Japan nuclear exclusion zone

TOKYO - UP TO 1,000 bodies of victims of Japan's quake and tsunami remain uncollected in the exclusion zone around a stricken nuclear plant because of radiation fears, a report said on Friday.

Citing police sources, Kyodo News said that authorities had intended to transport the bodies outside the 20km evacuation zone imposed around the Fukushima power station, but were reconsidering the plan.

The bodies had been 'exposed to high levels of radiation after death", the report quoted a source as saying, adding elevated levels of radioactivity were found on Sunday on the body of a victim about five kilometres from the plant.

Local police decided not to retrieve that body because of the radiation, the report said. Over 28,000 people have been confirmed dead or listed as missing since the twin natural disasters which hit on March 11, devastating the north-east coast and crippling the atomic plant, which has since been leaking radiation.

Workers have struggled to cool the plant, prevent a large-scale meltdown and dispose of thousands of tonnes of highly contaminated run-off water, while radioactive substances have tainted foodstuffs and groundwater nearby. Japan said on Thursday the plant would be scrapped following the crisis.

Authorities are considering decontaminating the bodies in the nuclear exclusion zone where they are found, but are concerned that the process could damage decomposing bodies further, hampering identification, Kyodo said. If the bodies were handed back to relatives without decontamination, cremating them could spread plumes containing radioactive substances, while burying them might contaminate the soil, the report added. -- AFP

US rules China dumps aluminium products

WASHINGTON - THE US Commerce Department said on Tuesday that it had found 29 Chinese companies guilty of dumping some US$500 million (S$630.5 million) worth of extruded aluminium products into the US market last year.

A department investigation concluded that the products, used in construction, vehicle parts, furniture and other goods, were being exported to the United States at roughly 33 per cent less than their fair value.

If the conclusion is upheld by the US International Trade Commission, the companies' products could be slapped with anti-dumping tariffs at that rate.

'Commerce determined that Chinese producers/exporters have sold aluminium extrusions in the United States at dumping margins ranging between 32.79 to 33.28 per cent,' the department said in a statement.

Several companies were also determined to have received significant subsidies that also merit penalty tariffs.

In 2009, China exported US$514 million worth of extruded aluminium products to the United States, falling slightly to US$503 million last year. -- AFP

Japan nuclear plant workers pushed to limit

People work in the control room of reactor No. 2 with restored lighting at the earthquake and tsunami affected Fukushima Daiichi nuclear power plant in Fukushima. -- PHOTO: REUTERS

OSAKA - WORN-OUT workers at Japan's stricken Fukushima nuclear plant are being pushed to the limit as high radiation levels endanger their lives and prolong their grim residency at the tsunami-ravaged facility.

After the March 11 earthquake and tsunami knocked out cooling systems at the plant, workers have toiled in toxic, dark environments laying electric cables, clearing rubble, hosing down overheating reactors and checking equipment.

Frequently spiking radiation levels have forced them to retreat from certain areas and extending their stay at the crippled plant central to Japan's worst ever nuclear accident.

Clad in protective suits, double-thickness gloves and masks and armed with flashlights, workers on shift rotations return from hours of hazardous toil to nap on floors or in corridors before returning to the grim darkness.

Huddling at the plant's 'quake-resistant' tower, resting workers lie on lead matting to prevent exposure to radiation which can rise up to 10 micro-sieverts an hour in that part of the complex.

'Workers sleep in conference rooms, hallways or near bathrooms. Each person is given one blanket, everyone sleeps on the floor in rows,' said Kazuma Yokota, a nuclear safety agency inspector stationed at the plant. 'We want to avoid staying too long as much as we can, because we are exposed to radiation every day. I've been exposed to 883 micro-sieverts in the past five days,' the exhausted-looking 39-year-old confided to broadcaster NHK. -- AFP

Thais to destroy potatoes with traces of radiation

The Thai Food and Drug Administration says the sweet potatoes had radiation levels well below the that which the World Health Organization considers hazardous. -- ST PHOTO: DESMOND WEE

BANGKOK - THAI authorities say they will destroy a shipment of sweet potatoes from Japan because they were found to have traces of radiation.

The Thai Food and Drug Administration says the sweet potatoes had radiation levels well below the that which the World Health Organization considers hazardous.

The tubers were found to have Iodine-131 levels of 15.25 Becquerel per kilogram. The hazardous threshold is 100 Becquerel per kilogram.

The agency said on Tuesday the shipment would be destroyed as a precaution.

Naturally occurring radiation can be found in almost everything in the world and the agency didn't say what normal levels of radiation in sweet potatoes would be nor whether any random tuber tested in Bangkok might have similar traces of radiation. -- AP

Radiation in seawater may be spreading in Japan

An aerial view shows Fukushima Daiichi nuclear power plant in Fukushima in this March 17, 2011 file photo. -- PHOTO: REUTERS

TOKYO - WORKERS at Japan's damaged nuclear plant raced to pump out contaminated water suspected of sending radioactivity levels soaring as officials warned on Monday that radiation seeping from the complex was spreading to seawater and soil.

The coastal power plant, located 220km north-east of Tokyo, has been leaking radiation since a magnitude-9.0 quake on March 11 triggered a tsunami that engulfed the complex. The wave knocked out power to the system that cools the dangerously hot nuclear fuel rods.

The frantic effort to get temperatures down and avert a widening disaster has been slowed and complicated by fires, explosions, leaks and dangerous spikes in radiation. Two workers were burned after wading into highly radioactive water, officials said.

On Monday, workers resumed the laborious yet urgent task of pumping out the hundreds of tons of radioactive water inside several buildings at the six-unit plant. The water must be removed and safely stored before work can continue to power up the plant's regular cooling system, nuclear safety officials said.

Contaminated water inside Unit 2 has tested at radiation levels some 100,000 times normal amounts, plant operator Tokyo Electric Power Co said.

Workers also discovered radioactive water in the deep trenches outside three units, with the airborne radiation levels outside Unit 2 exceeding 1,000 millisieverts per hour - more than four times the amount that the government considers safe for workers, Tepco said on Monday. -- AP

Plutonium detected in soil at Japan nuclear plant

SENDAI - PLUTONIUM has been detected in soil at a stricken nuclear plant in Japan and highly contaminated water has leaked from a reactor building, the operator said on Monday, fanning environmental fears.

Radiation worries have disrupted efforts to restart the cooling system of the Fukushima Daiichi plant, which was battered by a huge earthquake and tsunami on March 11 that left more than 28,000 people dead or missing.

With Japan struggling to contain its worst ever atomic crisis, France said its nuclear groups Areva and EDF had been asked to help. Plant operator Tokyo Electric Power Co said plutonium was found at five spots within the crippled facility, but stressed the levels were not believed to be a hazard to human health.

'Of the samples from five locations, we believe that there is a high possibility that at least two of them are directly linked with the current reactor accident,' a spokesman for Tokyo Electric Power Co said.

But he added: 'We believe the level is not serious enough to harm human health.' The level of plutonium was similar to that detected in Japan after neighbouring countries such as North Korea and China conducted nuclear experiments, the spokesman said.

Japan's Nuclear and Industrial Safety Agency said it was unclear which reactor the plutonium came from. Mr Hidehiko Nishiyama, a spokesman for the agency, said the detection of plutonium suggested 'certain damage to fuel rods', in comments carried by Kyodo News. -- AFP

Japan lacking radioactive water storage: US experts

WASHINGTON - JAPAN'S Fukushima nuclear plant may have run out of places to store radioactive water, US scientists said Monday after the plant operator reported leaks that could contaminate the ocean.

The plant is likely grappling with massive amounts of water, dumped by helicopter and water cannon for cooling after the power went out in the days following a massive earthquake and tsunami, said the Union of Concerned Scientists.

While workers have been able to stop injecting seawater into the reactor cores in units one, two and three, they face a new problem of how to deal with water that is now radioactive and in need of storage and treatment.

'They have a huge amount of radioactively contaminated water,' said Dr Dave Lochbaum of the UCS, noting that leaks have been detected in reactor buildings around units one, two and three at the complex.

'It is difficult to determine where that water is coming from. It obviously shouldn't be there in this quantity and it is posing some challenges to the workers,' said Dr Lochbaum.

'They need to get some control over that, some place to put it, some processing plant that can treat the water and remove as much radiation as possible,' he said. 'I don't want to criticise the fact that they needed to use that water, but the legacy of that problem is one they need to get their arms around quickly.' -- AFP

Radioactive iodine traces found in Seoul: Report

SEOUL - TRACES of radioactive iodine have been detected in Seoul following the nuclear crisis in Japan, a report said on Tuesday, though the level is not said to be harmful.

The state-run Korea Institute of Nuclear Safety (Kins) said it had found traces of radioactive iodine-131 in Seoul after analysing samples taken from the air in 12 places around South Korea, Yonhap news agency reported.

Kins said the amount of iodine was so small that there was no immediate risk to public health or the environment.

Japan's Fukushima Daiichi nuclear power plant was badly damaged by an earthquake and tsunami that hit the country on March 11 and radioactive material has leaked into the atmosphere.

Seawater near the plant has been found to contain radioactive iodine more than 1,850 times the legal limit, although it is not clear how the contamination spread to the Pacific Ocean.

The 9.0-magnitude quake and devastating tsunami that followed have left more than 28,000 people dead or missing. -- AFP

Tokyo nuclear operator seeking French help: Minister

PARIS - TOKYO Electric Power (Tepco), operator of Japan's stricken Fukushima nuclear plant, is seeking help from France to tackle the 'critical' situation, Industry Minister Eric Besson said on Monday.

'Tepco, for the first time, I'm pleased to say ... has asked for help from French industrial concerns,' the minister told RTL radio, specifying French energy giant EDF, nuclear group Areva and CEA, the atomic energy commission.

Mr Besson said the current situation at Fukushima, where highly radioactive water has leaked from a reactor turbine building following the March 11 earthquake and tsunami, was 'extremely critical'.

The water, found in an underground tunnel linked to the number two reactor at the Fukushima plant, showed a radiation reading of more than 1,000 millisieverts per hour, a Tepco official told reporters in Japan. A dose that strong can cause temporary radiation sickness with nausea and vomiting for people who are exposed.

The massive earthquake and tsunami knocked out the cooling systems of the plant's six reactors, triggering explosions and fires, releasing radiation and sparking global fears of a widening disaster. Plutonium has been detected in soil at the stricken nuclear plant.

Mr Besson said later in the day that Tepco had asked France 'to find a certain number of specialists in treating radioactive water, contaminated water'. He said Areva would send two specialists in the recuperation and treatment of radioactive water. -- AFP

Radiation scare at Japan nuclear plant

An aerial view shows Fukushima Daiichi nuclear power plant in Fukushima in this March 17, 2011 file photo. -- PHOTO: REUTERS

KITAKAMI (Japan) - DANGEROUS levels of radiation detected in water thought to be leaking from a stricken Japanese reactor dealt a new setback on Sunday to efforts to avert a nuclear disaster.

Radiation in puddles near reactor two at the Fukushima plant was more than 1,000 millisieverts per hour, forcing the evacuation of workers toiling to restore the cooling systems, operator Tokyo Electric Power (Tepco) said.

'It is an extremely high figure,' nuclear safety agency spokesman Hidehiko Nishiyama said, adding there was a 'high possibility' that the contaminated water had leaked from the reactor. A single dose of 1,000 millisieverts can cause temporary radiation sickness, including nausea and vomiting. An exposure of 100 millisieverts per year is considered the lowest level at which an increase in cancer risk is evident.

Tepco said the concentration of radioactive substances in the water was 100,000 times higher than would usually be found in water in a reactor core, correcting an earlier assessment which said it was 10 million times higher, Kyodo News reported.

Workers were trying to pinpoint the exact source of the radioactive water leak, but there are concerns that fuel rod vessels or their valves and pipes are damaged.

A key concern is how to safely pump away the highly radioactive water, but chief government spokesman Yukio Edano admitted progress at the site was slow. 'It will take some time in order to remove the water while ensuring the safety of workers,' Mr Edano told a press conference. -- AFP

Burning Questions about Japan Nuclear Disaster

 View more photos

A girl (above) sticks out her tongue at her mother as they are scanned for signs of radiation at the Azuma gymnastic hall in Fukushima, northern Japan, two Fridays ago. Radiation has been released into the atmosphere from the Fukushima nuclear plant on the country's north-east coast, which was badly damaged after a massive earthquake and tsunami on March 11. As part of attempts to prevent fuel from the plant from overheating and emitting dangerous levels of radiation, military fire trucks sprayed Unit 3 of the plant for the second day running last Friday. Unit 4 is in the background. The image above was taken from footage released by the Japan Defence Ministry

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The nuclear disaster in Japan's Fukushima prefecture has thrown up many questions that range from the risks of radiation to food and travel safety. The Sunday Times asked readers to send their queries via our Facebook and Twitter pages. Feng Zengkun finds answers to their questions.

Q Why were the nuclear plants so vulnerable?

The short answer is: Japan was incredibly unlucky. The nuclear plants have three sources of electricity that operate their vital cooling systems: power lines, a back-up system that runs on diesel, and a second back-up system made of physical batteries.

The earthquake destroyed the power lines, and the tsunami that followed wiped out the diesel back-up system. The battery system is designed to run for only a few hours while the first two systems are being fixed, but the unprecedented scale of the disaster meant there was no time.

Q Why were the nuclear reactors not shut down after the earthquake? Are they still generating electricity now, despite the danger of overheating?

The nuclear reactors were shut down. The problem is that radio-active fuel at the reactors remains very hot even when the plants are shut down, and requires constant cooling to prevent a meltdown. But the cooling systems do not work now, because there is no electricity.

This is also why workers at the plant have been dumping sea water into the reactors - to cool the radioactive material.

Q What is the worst-case scenario?

The containment structures that hold the nuclear fuel explode, and the reactors go into total meltdown and keep burning. This could make the disaster equal to the Chernobyl nuclear disaster of 1986 in terms of lives lost and the extent of radio-active contamination.

Even in Chernobyl, however, significant radiation did not spread beyond 800km from the reactors.

Q Who is monitoring the impact of the disaster in Singapore? What are they doing?

The National Environment Agency is monitoring the radiation levels in Singapore's atmosphere.

The Agri-Food and Veterinary Authority is testing food from Japan imported into Singapore.

National water agency PUB is testing the water supply here.

The Civil Aviation Authority of Singapore is checking on the potential impact on flights to and from Singapore.

Changi Airport also has contingency plans to deal with potential radiation at the airport.

Q How far can a radiation cloud travel? Can it reach travel destinations like the west coast of the United States, Hong Kong, Taiwan, North and South Korea, Thailand and Malaysia?

In the Chernobyl incident, radio-active clouds wafted across to Finland, Sweden, Poland and Austria - as far as 800km away.

All the countries listed above are more than 1,000km away. South Korea - which is the closest to Japan at 1,200km - has reported no change in its radiation levels. Singapore, at 5,300km from Japan, is extremely unlikely to be affected.

In any case, the radiation levels at Chernobyl were about 50 times worse than those at Fukushima.

Q I have heard there are two radioactive substances that have leaked - iodine and caesium. Radioactive iodine has a short half-life and dissipates quickly, but what about caesium? Exactly how does exposure to radiation cause cancer?

Iodine dissipates in about three to four months, but if the amount is small, it can dissipate within a month. Caesium survives at least 30 years. Radiation - whether through caesium or iodine - damages cells in the body. This causes mutations that can lead to cancer, especially if the cell repairs itself wrongly.

The threshold for cancer risk is 1,000 millisieverts, when radiation starts to affect the immune system. At 2,000 millisieverts, the digestive system is damaged and hair starts falling out in clumps. Death occurs at levels above 5,000 millisieverts.

So far, the highest radiation levels recorded at Fukushima have been about 400 millisieverts, much lower than the 10,000 millisieverts recorded at Chernobyl.

Elsewhere in Japan, readings are negligible, measuring a harmless 0.03 to 0.04 microsieverts an hour in Hokkaido, Kyoto and Osaka. 1,000 microsieverts equals 1 millisievert.

This is a fraction of the radiation a patient is exposed to during a medical X-ray (0.2 millisieverts) or a CT scan (12 millisieverts). Exposure to the sun over a year results in 2 millisieverts of radiation.

Q Is there existing technology that absorbs radiation? Is it worth buying potassium iodide, iodine solution, table salt or any other substance that is supposedly anti-radiation?

Iodine pills that contain potassium iodide can be taken to prevent

radioactive iodine from being absorbed. These work by saturating the thyroid gland with harmless iodine so it does not absorb dangerous, radioactive iodine.

There is absolutely no truth to the myth that eating table salt blocks radiation. People are mistaken that table salt contains potassium iodide, which blocks radiation, but it does not.

There is no technology to prevent the absorption of radioactive caesium.

However, people who are not in Fukushima and its immediate surrounding areas are extremely unlikely to be affected by either radioactive iodine or caesium.

There is no need for people in Singapore to stock up on or consume iodine pills, because Singapore is extremely unlikely to be affected by radiation from Japan.

Potassium iodide only works in the short term and is not a preventive treatment, as many hoarders in other countries seem to think. It can also cause allergic reactions, stomach upsets and swellings.

Q Is radiation 'contagious'?

Yes. People who are externally contaminated with radioactive material can contaminate other people or surfaces they touch. People who have radioactive dust on their clothing may spread the dust when they sit on chairs or hug other people.

People internally contaminated can expose those near them to radiation from the radioactive material in their bodies. The bodily fluids of an internally contaminated individual can contain radioactive materials. Coming into contact with these fluids can result in contamination.

Q Should I therefore avoid everyone who has just returned from Japan?

It depends where they were in Japan. People within a 20km zone of Fukushima should be tested for radiation at any public hospital, but people outside the zone are unlikely to be infected.

So far, in Singapore, about 12 returning travellers from Japan have tested negative for radiation.

Q Will there be acid rain? Is it corrosive?

Acid rain cannot be caused by Japan's nuclear fallout. Acid rain is caused by sulphur dioxide and nitrogen oxides, whereas the radio-active material from the nuclear plants is primarily radioactive iodine and caesium.

But the nuclear fallout can cause radioactive rain in the area near the reactor sites, which is also dangerous because it may cause cancer.

Radioactive rain is likely to be confined to Fukushima and its surrounding areas. There is too little radioactive material from the plants - even if the clouds were to travel they would lose their radio-activity quickly.

Q Is flying over the Pacific Ocean risky, especially with wind blowing radiation over it?

No. A plane's body and computer systems are radiation-resistant.

Also, a cloud with enough radioactive material to affect passengers in planes would be visible as a black cloud due to the concentration of particles, and planes would not fly through it.

Q What about the ocean? Can the radiation blowing out into the Pacific Ocean fall as rain and pollute fish and other produce from the sea?

No. The radiation currently produced by the reactors is too small. Any amount that falls into the ocean would be so diluted as to become harmless.

Q What does 'contaminated land' mean? Is the water contaminated? What about livestock and vegetables? I have heard that in the Chernobyl disaster, many people got sick from drinking tainted milk. Should I avoid all Japanese dairy products?

Contaminated land is land infected by radioactive material. Anything that radioactive particles fall on - including water, livestock, grass and fruit - becomes dangerous and can cause cancer if eaten or drunk in large quantities.

Experts say, however, that the current radiation from the nuclear plants is too small to affect food supplies throughout Japan. Singapore also conducts checks on every shipment of food imported from Japan.

Q This seems to be earthquake season. Will there be more earthquakes? Where are the fault lines and should I avoid them?

It is impossible to forecast earthquakes, but experts say there are several areas where high-magnitude earthquakes may occur in the next decade. These are:

The fault line between southern Taiwan and the northern Philippines

The Ryukyu Islands in Japan

Java

Sumatra

Northern Chile and southern Peru in South America.

Some experts believe earthquakes occur in clusters because of chain reactions in the earth, but this has not been scientifically proven.

Q When will it be safe to visit Japan again, and Tokyo in particular?
Radioactive iodine can survive for four months and radioactive caesium for 30 years, but any long-lasting damage is likely to be confined to Fukushima if the disaster does not worsen.

Readings taken outside Fukushima - in Tokyo, Hokkaido, Kyoto and Osaka, for example - have registered safe levels of radiation so far.

Q What can we do to help the tsunami and earthquake victims? In the light of reports that they are very short of fuel and food, how can fuel and food donations reach them?
There are collection tins at all FairPrice supermarkets and stores such as Cold Storage, Shop N Save, Giant hypermart and 7-Eleven, as well as Guardian Health and Beauty stores.

Cash donations can be made to the Singapore Red Cross Society in Penang Lane from Mondays to Fridays from 9.30am to 9pm, and on Saturdays and Sundays from 9.30am to 6pm.

Cheque donations can be made payable to the Singapore Red Cross Society and sent to 15 Penang Lane, Singapore 238486. You should indicate at the back of the cheque the following: Japan Disaster 2011, the donor's name, contact number and address.

SMS donations can be made by sending a text message to 75772. For every text message, $50 will be donated to the fund. Each SMS carries a charge of 30 cents.

From today to April 13, customers of OCBC Bank, DBS Bank and United Overseas Bank can donate via ATM, mobile and Internet banking. Donors can find out more by logging on to the banks' websites.

Anti-nuclear protesters march in Indian capital

Indian protesters belonging to the Anti-Nuclear Struggles Solidarity Forum hold placards and chant slogans during anti-nuclear protest, in New Delhi. -- PHOTO: AP

NEW DELHI - ABOUT 100 protesters marched to India's Parliament on Friday demanding that the government give up plans to build a large number of nuclear power plants because of safety issues underscored by Japan's nuclear crisis.

'The choice is clear - no nuclear,' chanted the protesters from the Anti-Nuclear Struggles Solidarity Forum, a coalition of more than a dozen groups.

They said radiation leaks at a Japanese nuclear complex hit by an earthquake and tsunami showed it was a dangerous form of energy generation.

The protest ended peacefully after the group marched through parts of the capital.

For decades India was forced into nuclear isolation as it pursued nuclear weapons as part of an arms race with neighbouring Pakistan.

India still refuses to sign the nuclear nonproliferation treaty, but the United States passed legislation in 2008 ending a ban on civilian nuclear trade with India. Since then, several foreign governments have been courting India to get a piece of its lucrative nuclear energy market. -- AP

Tokyo luxury hotel to house nuclear plant evacuees

OSAKA - A 700-ROOM Tokyo luxury hotel tower due for demolition this year will first be used as an evacuation centre for people who fled areas near a stricken nuclear plant, a city official said on Friday.

The 40-storey tower of the Grand Prince Hotel Akasaka will house people driven away from their homes near the coastal Fukushima atomic power station, 250km north-east of the megacity, by the radiation threat.

The Akasaka venue - designed by the late architect Kenzo Tange and once a favourite haunt of politicians and celebrities - will accommodate 1,600 people from early April until late June, the Tokyo metropolitan government said.

'The Tokyo government expects to announce as early as next week details such as how rooms will be allocated,' a Tokyo government official told AFP.

Other large venues in the capital have also opened their doors to evacuees from the north-east of Honshu island, where a massive earthquake and tsunami on March 11 wiped out entire towns and made hundreds of thousands homeless.

The Tokyo Budokan venue, the Ajinomoto Stadium and Japan's largest convention centre, the futuristic Tokyo Big Sight, have also been providing temporary shelter for a total of 573 evacuees as of Friday, the official said. -- AFP

Fukushima seawater may affect reactor cooling: France

PARIS - EMERGENCY use of seawater at Fukushima could harm longer-term efforts to cool the plant's crippled reactors, France's nuclear watchdog said on Wednesday.

The agency said it was 'concerned' that salt from seawater used extensively to cool the reactor cores could be corrosive or build up in crystalline layers inside heat exchangers and valves, hampering their efficiency.

This equipment will be needed when pumping power is restored at the plant and coolant is recirculated as normal, the Institute for Radiological Protection and Nuclear Safety (IRSN) said.

'The impacts from the presence of salt in the water could affect the cooling of the fuel within a very short time,' the IRSN said. 'The general recommendation is to rebuild stocks of freshwater on site.'

Engineers resorted to the desperate step of injecting seawater into three reactors to cover fuel rods that dangerously overheat if exposed to air. Pumping capacity at the plant was knocked by the March 11 earthquake and tsunami that struck north-eastern Honshu.

Separately, the IRSN published data about radioactivity contamination found in spinach and leeks in Tochigi, Ibaragi and Gunma prefectures. The figures - which the agency said it had received indirectly - showed that on March 19, iodine 131 contamination was highest in spinach from Ibaragi, at up to 11,000 Becquerels per kilo. This compares with Japan's maximum permitted limit for selling or eating food of 2,000 Bq/kilo. -- AFP

Japan resumes dousing smouldering nuclear plant

OSAKA - EMERGENCY crew using fire engines again aimed their high-pressure water jets at a quake-hit and charred nuclear reactor in Japan on Thursday, a day after a plume of dark smoke forced them to evacuate.

Workers have struggled to avert a meltdown at the Fukushima plant north-east of Tokyo that has belched radiation, forcing tens of thousands to evacuate, contaminating farm produce and drinking water, and sparking wide anxiety.

White steam was seen rising from four of the six reactors in the morning. Workers had been pulled back on Wednesday after dark smoke rose from the number three reactor unit, which was badly hit by the massive 9.0-magnitude earthquake and towering tsunami which battered north-east Japan on March 11.

The quake severed external power to the plant. Reactors one to three, which were operating at the time, automatically shut down but the tsunami knocked out the backup generators and the cooling systems failed.

Early on Thursday the Tokyo fire department engines again aimed their powerful seawater jets at the site to top up a spent fuel pool inside the unit. The focus is on the number three reactor, of special concern since it uses volatile uranium-plutonium fuel. Retopping the containment pool aims to stop it from being exposed to air where it could release large-scale radiation.

Engineers have now linked up an external electricity supply to all six reactors and are testing system components and equipment in an effort to soon restart the cooling systems and stabilise the reactors. -- AFP