Archive for Thursday, March 17, 2011

Japan military begins dumping water on reactor

March 17, 2011

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— Japanese military helicopters dumped loads of seawater onto a stricken nuclear reactor today, trying to avoid full meltdowns as plant operators said they were close to finishing a new power line that could restore cooling systems and ease the crisis.

U.S. officials in Washington, meanwhile, warned that the Fukushima Dai-ichi plant in northeastern Japan may be on the verge of spewing more radioactive material because water was gone from a storage pool that keeps spent nuclear fuel rods from overheating.

The troubles at several of the plant’s reactors were set off when last week’s earthquake and tsunami knocked out power and ruined backup generators needed for their cooling systems, adding a major nuclear crisis for Japan as it dealt with twin natural disasters that killed more than 10,000 people and left hundreds of thousands homeless.

A Japanese military CH-47 Chinook helicopter began dumping seawater on the damaged reactor of Unit 3 at the Fukushima complex at 9:48 a.m., said defense ministry spokeswoman Kazumi Toyama. The aircraft dumped at least four loads on the reactor, though much of the water appeared to be dispersed in the wind.

At least a dozen more loads were planned in the 40 minutes that each crew can operate before switching to limit radiation exposure, the ministry said.

The dumping was intended both to help cool the reactor and to replenish water in a pool holding spent fuel rods, Toyama said. The plant’s owner, Tokyo Electric Power Co., said earlier that the pool was nearly empty, which might cause the rods to overheat.

The comments from U.S. officials indicated there were similar problems at another unit of the Dai-ichi complex.

U.S. Nuclear Regulatory Commission Chairman Gregory Jaczko said at a congressional hearing in Washington that all the water was gone from a separate spent fuel pool at the plant’s Unit 4. Japanese officials expressed similar worries about that unit, but that it was impossible to be sure of its status.

Emergency workers were forced to retreat from the plant Wednesday when radiation levels soared, losing precious time. They resumed work after radiation levels dropped, but much of the monitoring equipment in the plant is inoperable, complicating efforts to assess the situation.

“We are afraid that the water level at unit 4 is the lowest,” said Hikaru Kuroda, facilities management official at Tokyo Electric Power Co. But he added, “Because we cannot get near it, the only way to monitor the situation is visually from far away.”

The storage pools need a constant source of cooling water. Even when removed from reactors, the rods retain radioactivity and must be cooled for months, possibly longer, to prevent them from posing a threat of meltdown.

Japanese officials raised hopes of easing the crisis earlier today, saying that they may be close to bringing power back to the plant and restoring the reactors’ cooling systems.

The new power line would revive electric-powered pumps, allowing the company to control the rising temperatures and pressure that have led to at least partial meltdowns in three reactors. The company is also trying to repair its existing disabled power line.

Comments

Richard Heckler 4 years, 2 months ago

No contemporary energy source is as environmentally irresponsible, imposes such a high liability on taxpayers, or is as dangerous as nuclear power.

Industry efforts to "greenwash" nuclear energy make a mockery of clean energy goals.

Although nuclear reactors do not emit carbon dioxide, promoting nuclear risks to reduce greenhouse emissions is the classic jump from the frying pan into the fire!

The Real Dirt on "Clean" Nuclear Energy

* The mining, milling and enrichment of uranium into nuclear fuel are extremely energy-intensive and result in the emission of carbon dioxide into the atmosphere from the burning of fossil fuels.

* Estimated "energy recovery time" for a nuclear power plant is about 10 to 18 years, depending on the richness of uranium ores mined for fuel. This means that a nuclear power plant must operate for at least a decade before all the energy consumed to build and fuel the plant has been earned back and the power station begins to produce net energy. By comparison, wind power takes less than a year to yield net energy, and solar or photovoltaic power nets energy in less than three years.

* The Nuclear Regulatory Commission has calculated that collective radiation doses amounting to 12 cancer deaths can be expected for each 20-year term a reactor operates, as a result of radioactive emissions from the nuclear fuel cycle and routine reactor operations. This calculation assumes no unplanned accidents and does not consider radiation releases from high-level nuclear waste "disposal" activities. Nor are nonfatal health impacts related to radiation exposure counted in this tally.

* Thermal pollution from nuclear power plants adversely affects marine ecosystems. "Once-through" cooling systems in use at half the U.S. nuclear reactors discharge billions of gallons of water per day at temperatures up to 25 degrees Fahrenheit hotter than the water into which it flows.

Richard Heckler 4 years, 2 months ago

Safety and Security Risks

* Nuclear power poses unique safety and security threats, relative to other sources of electricity. A severe accident or attack at a nuclear plant could be catastrophic.

* Accidents do happen, as history has taught us at Chernobyl, Three Mile Island and, most recently, the Davis-Besse nuclear plant near Toledo, Ohio, which came dangerously close to disaster when acid corroded a hole in its reactor head. Don’t forget reports that the al Qaeda terrorist organization considered an attack on a U.S. nuclear power station.

* The insurance industry won’t insure against nuclear power plant accidents. Nuclear power plant operators rely on a government-backed "Price-Anderson" insurance scheme that limits their liability in the event of an accident or attack.

And Expensive Too!

The Department of Energy admits that "Economic viability for a nuclear plant is difficult to demonstrate." Since the inception of commercial nuclear power in the United States 50 years ago, this industry has been propped up by huge government subsidies.

Throwing more tax dollars at nuclear power will not make it safer, cleaner or more economical. Further, these subsidies to a mature industry distort electricity markets by granting nuclear power an unfair and undesirable advantage over safe, clean energy alternatives.

Flap Doodle 4 years, 2 months ago

Are you forgetting that attribution thing again, planet-killer merrill? Plagiarism is dumb and irresponsible!!!!!!!!

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