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Critics of Japanese Storage System See a Worse-Than-Chernobyl Scenario Ahead
by Faye Flam via stele - Philadelphia Inquirer Saturday, Mar 19 2011, 8:51pm
international /
environment /
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With attention focused on tons of radioactive spent fuel that may have ignited, some experts say the Japanese will be lucky if the stricken Fukushima plant creates a disaster only the size of Chernobyl in 1986. These spent fuel rods are now being blamed for the radioactive releases over Japan. While the reactor cores are encased in bulky containment vessels, spent fuel is separated from the environment only by the water in the pools, said former nuclear engineer David Lochbaum of the Union of Concerned Scientists in Cambridge, Mass.
That those spent fuel rods were even kept at the Japanese plant is controversial. Some used rods remain hot enough to ignite their metal coatings and release dangerous plumes of radioactive gases and dust.
Critics such as Lochbaum argue this storage system, which is widely used in the United States, poses an unnecessary hazard. Indeed, most of the 62,500 metric tons of spent fuel in the United States is stored in similar pools on site at power plants, including Limerick in Montgomery County, Peach Bottom in York County, Oyster Creek plant in Ocean County, and the Salem and Hope Creek plants in Salem County.
Some experts argue the system is not inherently flawed.
Local nuclear plants are designed to withstand earthquakes, terrorist attacks, and other potential disasters, said Krishna "Kris" Singh, an engineer and chief executive officer of Marlton-based Holtec who designed the nuclear-waste storage systems used in most local plants.
Singh said people in the East should not panic, considering how astronomically unlikely it is that a tsunami or magnitude-9 earthquake would ever hit the Mid-Atlantic region.
His firm has been asked to reevaluate storage pools at the Diablo Canyon plant in California, where such a large quake remains possible. He said that plant's overall design was more earthquake-proof than was Fukushima.
Putting rods in swimming-pool-size concrete tanks was intended only to serve as temporary storage, Lochbaum said. Before the mid-1970s, much of the country's nuclear waste was sent for reprocessing, a type of recycling that has fallen out of favor because it produces weapons-grade plutonium.
Lochbaum said his opposition to the overuse of on-site "wet" storage led him to leave the industry and join the Union of Concerned Scientists, a group focused on nuclear safety and other environmental concerns.
Many pools at U.S. plants routinely store as much as 10 times as much waste as pools at Fukushima.
Singh and other experts said it was too early to tell why the water levels in the spent pools at Fukushima appear to have dropped enough to expose some of the fuel. The thick concrete that contains the water might have been damaged in the earthquake or water may have sloshed out.
The pools are put on the top floor of the reactor buildings - a placement that is considered an engineering choice, according to a spokesman for the Nuclear Energy Institute.
Several of the spent pools at Fukushima were reportedly losing water, but the one at Reactor 4 is causing the most concern because it carries the most fuel and the hottest spent fuel - 135 tons of rods, many of them removed just in December.
Although the fuel in these pools is considered spent, it's still so radioactive that without cooling, it will spontaneously heat up to between 1,500 and 1,800 degrees, enough to ignite the metal cladding that surrounds the fuel pellets. That burning releases explosive quantities of hydrogen gas, which can further damage the fuel and the storage pool.
As the rods heat up, Lochbaum said, gases laced with radioactive substances expand inside the rods. If the metal is breached, these gases are lofted into the atmosphere. If the temperature gets hot enough, fuel pellets will begin to crumble and release dust-size particles containing various radioactive by-products.
According to a briefing by the Physicians for Social Responsibility, those releases can contain strontium-90, which tends to concentrate in bones and cause bone cancer. Some of the fuel at Fukushima contains plutonium, which can cause lung cancer.
Also of grave concern is cesium-137, which has a long half-life and can persist in the environment for more than a century. Cesium-137 released in the Chernobyl disaster rendered huge swaths of the Ukraine uninhabitable.
The United States has never come to any agreement on how to deal with nuclear waste, which can remain radioactive for millions of years.
Singh said he still believed storage in pools can be done safely, especially as technology advances. "Clearly the earthquake was of much greater severity than the plant was designed for," he said.
Singh said his company was creating a new system that would shield the spent fuel. "We're designing it so you'll be able to walk into the building even if you had a horrible scenario like this one," he said.
He has designed aluminum racks that allow U.S. nuclear plants to store many more spent fuel rods in the same pools. Singh's company also supplies a system of dry storage, in which waste is sealed in casks. Lochbaum and others at the Union of Concerned Scientists consider this a much safer alternative in the face of earthquakes, terrorist attacks, or other threats still unknown.
Singh's nuclear-power innovations have led to more than 17 patents. His company's storage systems are used at 80 of the country's 104 nuclear plants. A technological optimist, Singh has recently donated $20 million to his alma mater, the University of Pennsylvania, for a new building devoted to nanotechnology.
Until the 1970s, spent fuel rods were partially recycled, the various components were separated out, leaving behind weapons-grade plutonium and uranium. But once the United States had enough plutonium to destroy the world 100 times over, the government prohibited reprocessing.
The Nuclear Energy Institute, an industry group, favors a combination of reprocessing, dry storage, and transfer to an ultimate resting place at Yucca Mountain in Nevada. For years, public opposition prevented any waste from being stored there, and in 2009 the Obama administration ruled against using the site. But the utilities and industry group continue to push for it.
Whatever happens to the nuclear energy industry in the wake of the Fukushima disaster, some 60,000 metric tons of nuclear waste will remain with us.
© 2011 Philadelphia Inquirer
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Radioactive material found in Japanese Milk, Food and Water
by wire services via reed - The Guardian UK Saturday, Mar 19 2011, 9:24pm
Increased levels of radiation-toxicity have been detected in Food products in Tokyo and other affected areas in Japan. The authorities in characteristic denial and minimisation, downplayed the threat as usual. Nevertheless, the FACT remains; all poisonous radioactive material is detrimental to human health.
If the threat is minimal, as lying officials claim [and culpable directors of TEPCO, Tokyo Electric, continue to avoid responsibility/seppuku] then officials and TEPCO directors should be made to consume irradiated foods regularly. Integrity would soon be restored in Japan as a result.
The Japanese government has reported that trace amounts of radioactive iodine have been detected in tap water in Tokyo and five other areas, amid concerns about leaks from the crippled Fukushima nuclear power station.
The ministry says the amounts did not exceed government safety limits, but the announcement has added to safety fears among the Japanese people. Earlier in the day, Japan banned the sale of food products from near Fukushima after finding elevated radiation levels in spinach and milk from the area's farms.
The International Atomic Energy Agency said: "Though radioactive iodine has a short half-life of about eight days and decays naturally within a matter of weeks, there is a short-term risk to human health if radioactive iodine in food is absorbed into the human body."
Tainted milk was found 30km (20 miles) from the plant and contaminated spinach was collected up to 100km (65 miles) to the south.
Chief cabinet secretary Yukio Edano told reporters in Tokyo that the radiation levels exceeded the limits allowed by the government, but the products "pose no immediate health risk" and testing was being done on other foods..
"It's not like if you ate it right away you would be harmed," Edano said. "It would not be good to continue to eat it for some time."
Edano said the amount of radiation detected in the milk was the equivalent to one CT scan – the series of X-rays used for medical tests – if consumed continually for a year.
Low levels of radiation have been detected well beyond Tokyo, which is 220km south of the plant, but hazardous levels have been limited to the plant itself.
The food scare is the latest consequence of the cascade of disasters unleashed by the earthquake on 11 March.
Emergency teams scrambled on Saturday to restore power to the Fukushima plant so it could cool dangerously overheated fuel.
Firefighters pumped tons of water directly from the ocean into the cooling pool for used fuel rods at the plant's unit 3. The rods are at risk of burning up and sending a broad release of radioactive material into the environment.
Just outside the bustling disaster response centre in the city of Fukushima, 60km north-west of the plant, government nuclear specialist Kazuya Konno was able to take only a three-minute break for his first meeting with his wife Junko and their children since the earthquake.
"It's very nervewracking. We really don't know what is going to become of our city," Junko told Associated Press. "Like most other people, we have been staying indoors unless we have to go out."
She brought her husband a small backpack with a change of clothes and snacks. The girls, aged four and six and wearing pink surgical masks decorated with Mickey Mouse, gave their father hugs.
In his latest ministerial update from Tokyo, Edano said: "The situation at the nuclear complex still remains unpredictable. But at least we are preventing things from deteriorating."
A fire truck with a high-pressure cannon parked outside the plant's unit 3 began shooting a continuous arc of water nonstop into the pool for seven hours. Because of high radiation levels, firefighters will only go to the truck every three hours when it needs to be refueled. They expect to pump about 1,400 tons of water, nearly the capacity of the pool.
Hidehiko Nishiyama of Japan's Nuclear and Industrial Safety Agency said backup power systems at the plant had been improperly protected, leaving them vulnerable to the tsunami that ravaged the north-eastern coast of Japale.
The failure enabled uranium fuel to overheat and was a "main cause" of the crisis, Nishiyama said. "I cannot say whether it was a human error, but we should examine the case closely."
A spokesman for Tokyo Electric, which owns and runs the complex, said it was protected against tsunamis of up to five metres (16ft) but a six-metre wave of water struck Fukushima on 11 March.
Plant operators said they would reconnect four of the plant's six reactor units to a power grid on Saturday. Workers have to methodically work through badly damaged and deeply complex electrical systems to make the final linkups without setting off a spark and potentially an explosion.
"Most of the motors and switchboards were submerged by the tsunami and they cannot be used," Nishiyama said.
Even once the power is reconnected, it is not clear if the cooling systems will still work.
The storage pools need a constant source of cooling water. Even when removed from reactors, uranium rods are still extremely hot and must be cooled for months, possibly longer, to prevent them from heating up again and emitting radioactivity.
Meanwhile, some Britons in the country have begun their journey back to the UK to escape from radiation fears, power shortages, business closures and a lack of food in shops.
Buses and planes ferried people to safety on Friday, with 24 British nationals leaving tsunami-flattened Sendai on two coaches heading for Tokyo.
The Foreign Office block-booked seats for Britons wanting to fly home on commercial flights, the first of which was a Cathay Pacific flight to Hong Kong, and said two other flights to Hong Kong would be made available on Saturday.
Those directly affected by last week's devastating earthquake and tsunami can fly free of charge, but people wishing to leave Japan who have not been directly affected will pay about £600 per seat.
© 2011 Guardian News and Media Limited
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