life in general: (part 3) japanquake11mar11: japan's self-inflicted nuclear danger

The whole of Japan and its nearby sea area lies above a seismic hotspot. Yet Japan has several nuclear power plants that run on dangerously radioactive nuclear fuels. It is a shame on the past government officials and industry officials who were arrogant enough to think they could design nuclear power plants that would withstand a very powerful earthquake such as the one that hit Japan on 11 March. 

Here is a technical update by another blogger on the nuclear emergency Japan is facing currently:

http://mariogregorio.wordpress.com/2011/03/13/west-coast-usa-danger-if-japan-nuclear-reactor-meltdown/

............Following the fifth largest earthquake in recorded world history, a magnitude 8.9 earthquake, has resulted in the closure of all Japan’s nuclear power reactors, one of which, the Fukushima reactor, is overheating and in danger of a meltdown if coolant is not restored soon. It’s like a pressure cooker… when you have something generating heat and you don’t cool it off or release the steam…

Reported from abc NEWS, Scientists said that even though the reactor had stopped producing energy, its fuel continues to generate heat and needs steady levels of coolant to prevent it from overheating and triggering a dangerous cascade of events.

They go on to say, “Up to 100 percent of the volatile radioactive Cesium-137 content of the pools could go up in flames and smoke, to blow downwind over large distances,”

“Given the large quantity of irradiated nuclear fuel in the pool, the radioactivity release could be worse than the Chernobyl nuclear reactor catastrophe of 25 years ago.” said Kevin Kamps, a nuclear waste specialist.

Fukushima I (there are two plant locations) is one of the 25 largest nuclear power stations in the world.

How would a nuclear plant meltdown unfold?

Control rods are driven back down into the core upon emergency (if rods don’t make it all the way… trouble)The coolant (water) could cease if backup systems fail (electricity, pumps, generators, batteries)Reactor continues to produce heatNumerous venting valve systems would release pressure above ~1,000 psi into containment vesselEventually the uranium fuel encasement metal will melt (2,200 deg F)Radioactive contamination then released into the reactor vesselRadiation escapes into an outer, concrete containment buildingRadiation escapes into the environment.

Not only would such a disaster be horrible for the local region and Japan, but other countries, namely the U.S. would be effected next by airborne radiation particles, the magnitude of which is yet to be determined.

.......
Update,

BBC News Asia-Pacific is now reporting that radiation levels inside the nuclear reactor are 1,000 times of normal, and there are now high levels (unspecified) ‘outside’ of the nuclear reactor plant. They report that people are being evacuated in an approximate 6-mile perimeter.

Update,
The Washington Post reports that a second nuclear reactor in the Fukushima power plant is also affected. The plant has a total of six reactors. Reports only a few hours left on battery power for cooling systems.

Update,
Clarification from NHK Wolrd News Japan… a second location, Fukushima II, not far from the Fukushima I nuclear power plant, is also experiencing cooling problems. The government’s Nuclear and Industrial Safety Agency said equipment failures have made it impossible to cool 3 of the plant’s 4 reactors. (Translation: ‘impossible’ is not a good word).

Update,
Reuters is now reporting that Tokyo Electric Power Company has lost ability to control pressure at some of the reactors at its Fukushima II (Daini) plant nearby the Daiichi power plant (Fukushima I), both suffering from core cooling problems. If battery power at Fukushima II is depleted before AC power is restored, the plant will stop supplying water to the core and the cooling water level in the reactor core will drop.

Update,
Kyodo news reports that the cooling system has now failed at three nuclear reactors at Fukushima II, and the coolant water temperature has reached boiling level.

Update,
Kyodo news reports, “the operator of the two plants in Fukushima Prefecture is set to release pressure in containers housing their reactors under an unprecedented government order, so as to avoid the plants sustaining damage and losing their critical containment function.” …”the action would involve the release of steam that would likely include radioactive materials”

Update,
From Kyodo news, Japan, URGENT: Concerns of core partially melting at Fukushima nuke plant. The core at Fukushima No. 1 nuclear power plant’s No. 1 reactor may be partially melting, the nuclear safety agency said Saturday.

Reuters, Japan authorities: TEPCO plant fuel rods may have melted -Jiji, …could develop into a breach of the nuclear reactor vessel and the question then becomes one of how strong the containment structure around the vessel is and whether it has been undermined by the earthquake