Nuclear - March 12
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Japan battles to contain nuclear crisis after huge quake
Chris Meyers and Kim Kyung-hoon, Reuters
FUKUSHIMA, Japan - Japan scrambled on Saturday to reduce pressure in two nuclear plants damaged after a massive earthquake and tsunami struck its northeast coast probably killing at least 1,300 people.
... The government warned of a possible radiation leak as authorities began trying to reduce pressure at damaged two nuclear plants, sending tens of thousands of residents out of the area to avoid possible contamination.
... "No Chernobyl is possible at a light water reactor. Loss of coolant means a temperature rise, but it also will stop the reaction," Naoto Sekimura, a professor at the University of Tokyo, said.
"Even in the worst-case scenario, that would mean some radioactive leakage and equipment damage, but not an explosion. If venting is done carefully, there will be little leakage. Certainly not beyond the 3 km radius."
(11 March 2011)
On the Brink of Meltdown: The Fukushima Nuclear Power Plant
Robert Alvarez, Institute for Policy Studies
The devastating Japanese quake and its outcome could generate a political tsunami here in the United States.
In the aftermath of the largest earthquake to occur in Japan in recorded history, 5,800 residents living within five miles of six reactors at the Fukushima nuclear station have been advised to evacuate and people living within 15 miles of the plant are advised to remain indoors.
Plant operators haven't been able to cool down the core of one reactor containing enormous amounts of radioactivity because of failed back-up diesel generators required for the emergency cooling. In a race against time, the power company and the Japanese military are flying in nine emergency generators. Secretary of State Hillary Clinton announced today that the U.S. Air Force has provided cooling water for the troubled reactor. Complicating matters, Japan's Meteorological Agency has declared the area to be at high risk of being hit by a tsunami.
The plant was operating at full power when the quake hit and even though control rods were automatically inserted to halt the nuclear reaction, the reactor core remains very hot. Even with a fully functioning emergency core cooling system, it would take several hours for the reactor core to cool and stabilize. If emergency cooling isn't restored, the risks of a core melt, and release of radioactivity into the environment is significantly increased. Also, it's not clear if piping and electrically distribution systems inside the plant have been damaged. If so, that would interfere with reactor cooling.
A senior U.S. nuclear power technician tells me the window of time before serious problems arise is between 12 and 24 hours.
Early on, Japanese nuclear officials provided reassurances that no radiation had been released. However, because the reactor remains at a very high temperature, radiation levels are rising on the turbine building – forcing to plant operators to vent radioactive steam into the environment.
(11 March 2011)
Report: 2 Japanese plants struggling to cool radioactive material
CNN Wire Staff
Reactors at two Japanese power plants can no longer cool radioactive substances, a major electric company said Saturday, according to a news agency report that added that atomic material may have leaked out of one of the plants.
Citing the Tokyo Electric Power Co., Japan's Kyodo News Agency said that radioactive substances may have seeped out of the Fukushima Daiichi nuclear reactors, about 160 miles (260 kilometers) north of Tokyo.
Potentially dangerous problems in cooling radioactive material appear to have cropped up there, as well as at another of the Tokyo Electric Power Company's nuclear plants, Ichiro Fujisaki, Japan's ambassador to the United States, confirmed to CNN. Both plants are named Fukushima Daiichi and both have nuclear reactors, but they are separate facilities.
... Temperatures of that plant's coolant water was hotter than 100 degrees Celsius (212 degrees Fahrenheit), the news agency said, an indication that the cooling system wasn't working.
(11 March 2011)
Spent nuclear fuel; more opportunity than threat
Rolf E. Westgard, Star Tribune
By wide margins, the Minnesota House and Senate have each passed a bill which removes our state’s ban on issuing certificates of need for new nuclear power plants. These bills now have to be reconciled into one, approved, and sent to governor Dayton for veto or signature. The house bill contains an amendment from Representative Phyllis Kahn which bars any new nuclear plant program which would produce ‘weapons grade’ plutonium during reprocessing of spent nuclear fuel pellets(nuclear waste).
Gov. Dayton and many others are concerned about the long term storage of radioactive spent fuel pellets. The French deal with this issue for their 58 nuclear plants by reprocessing the spent fuel. 95% of the material, including some fissionable plutonium, is recycled into new fuel, and the dangerous 5% is vitrified into glass cylinders for storage. All of those cylinders from 58 reactors are stored in the floor of one large room at La Hague, France. They will eventually go to permanent geologic storage.
During their 5 years as fuel in commercial power reactors, the pellets produce some plutonium which joins uranium 235(U235) as additional fuel, extending fuel life. After 5 years, the pellet’s percent of U235 and plutonium declines from about 5% to 2%, and it no longer sustains the chain reaction; but the 2% is very valuable reactor fuel when recycled.
The plutonium which remains in the spent pellets is a mix of several plutonium isotopes, still useful as reactor fuel, but not useful in a nuclear weapon. A little more than half of the plutonium is Pu239 which needs to be at 93% for the plutonium to be weapons grade. If there is more than 20% Pu240, which tends to fission spontaneously, all the plutonium is reactor grade and “entirely unsuitable for use in a bomb” per the World Nuclear Association. The plutonium in spent fuel pellets from commercial reactors contains 24% Pu240, as well as other plutonium isotopes which inhibit bomb making. That plutonium is reactor grade, not weapons grade.
Representative Kahn’s carefully drawn amendment, she is a physics graduate, will not limit new commercial reactors, since they don’t produce weapons grade plutonium.
The legislative change of heart about nuclear energy may reflect an understanding of what Xcel Energy pointed out in a recent insert included in all of its customer bills. The brochure titled ‘Your Electricity’, listed nuclear energy as its most reliable and one of its cheapest fuel sources. Even the expensive new nuclear plants are competitive when we consider their productivity. The $5 billion 1200 megawatt nuclear plants being sold and installed by China and South Korea will produce 600 billion kilowatt hours(kwh) over their 60 year specification life. That’s less than a penny per kwh capital cost, excluding interest. Fuel cost is less than a penny per kwh.
AS Dale Klein, Associate Director of the University of Texas Energy Institute, recently told the American Association for the Advancement of Science, “Spent fuel is not waste. The waste is our failure to tap into this valuable and abundant domestic source of clean energy in a systematic way.” Dr. Klein went on to point out that “failure to reprocess spent fuel is an enormous waste of potential energy.”
Reprocessing not only recovers significant energy value from spent fuel, it substantially reduces the volume and radiotoxicity of high-level nuclear waste. The French have demonstrated that it works. It is time that we got on with it.
(11 March 2011)
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