8.9 Earthquake has struck Japan

Jordan Hartley said:
Fox news is reporting that a state of emergency has been declared for the nuclear plant :/
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That happened nearly a day ago

Fukushima 1: Fuel Meltdown Begins


The Nuclear and Industrial Safety Agency (NISA) of the Ministry of Economy and Industry (MITI) has just announced that near Unit 1 of the Fukushima 1 Nuclear Power Plant, a radioactive element called "cesium," which results from nuclear fission, has been detected, so it believes that a part of the nuclear fuel at the reactor core of Unit 1 has melted down.


Edit: Kyodo is now reporting that pressure successfully released from Fukushima No. 1 reactor:

Jordan Hartley said:
Fox news is reporting that a state of emergency has been declared for 5 nuclear plants :/

Last edited by Jordan Hartley; Today at 12:41 AM.
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Ah. :) it's actually 5 reactors at two plants and not 5 plants.
 
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Isn't the whole purpose of a containment chamber to, well, contain most of the radiation in the case of a meltdown? If this is correct, then, even if we are seeing a meltdown, the consequences will be nothing like Chernobyl as long as the containment system does its job. With reports that the pressure has been relieved, is there any reason to think that this meltdown will get through the containment chamber in any meaningful way (that is, more than a slight radiation release that'll affect the area within a few miles of the reactor)? Again, I'm know particularly knowledgeable in nuke tech, so I'm all ears for those who know more than I!
 
Generally yes, From what I can find it may depend on whether any damage is done to the containment by the quake and if they can keep pressure down and keep from damaging it. I also heard this was a rather old unit? 60's?

My only concern is without a breach how did the cesium get out without a venting?
 
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Video of town of 70,000 wiped clean -> CNN video. Towards the end, you can see just a lot of bare foundations, quite similar to what the Bolivar peninsula in Texas looked like after Hurricane Ike (example here). I know Japan is extremely capable in terms of earthquake damage mitigation and tsunami preparation, but I fear the actual death toll may end up an order of magnitude larger than it is now (200-1000 fatalities from what I've read).
 
Agree, I have seen so many videos of the walls of water and debris and such tackling moving vehicles and the houses that I would not be at all surprised if in the end it went over 100,000 dead.


Also:
The government's Nuclear and Industrial Safety Agency says 2 radioactive substances, cesium and radioactive iodine, have now been detected near the number one reactor at the Fukushima nuclear power station.
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Having looked around other locations online (social media, news aggregators,etc.), I'm seeing the danger of some of the numbers being thrown around without being given any context. Since I'm not well-versed in nuclear physics, I'm not sure how I'm supposed to interpret what "1.5 times normal pressure" is supposed to mean, for example. Well, we may know what it means, but it's not possible to interpret it unless we have some context or perpsective. If the containment vessels are designed to withstand 5 times normal pressure, then at least I have some perspective on what "1.5 times normal pressure" means. What are the design specs of the containment chamber? Is this really that bad, or is it legitimately a bad sign? If radiative vapor is released (which sounds bad), what is actual risk to humans considering dispersion of whatever level of radiation was released? Of course, the news anchors and reporters likely have no idea what most of the numbers mean either, so that means we have to wait until those who DO know what they mean can be interviewed. In the mean time, it *tends* to have the potential to cause unnecessary panic. Until then, I'm left to remain cautious and hesitant of reacting to any of the numbers until I can learn enough to know what the numbers actually mean (i.e. context and perspective).

This reminds me of hearing that "product A or activity B doubles your risk of cancer" without explaining that the cancer is extraordinarily rare, and, thus, a doubling of the risk and incidence isn't likely to affect many. I'm reading a lot of lines like "Well, I have no idea what the numbers mean, but an XX increase in YY can't be good". While true, I worry that many folks (again, myself included) can't really know how to react to the numbers without proper perspective.

[The above are most hypothetical questions, FWIW, to illustrate a point]
 
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News is popping with reports of an explosion with several injuries and smoke rising from the Fukushima nuclear plant. Twitter and a few news sites lighting up with it.

I think it was near maybe but not at the plant. The news orgs are so eager to break first they are flying of the handles.
 
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I worked in nuclear power in the navy, so our containment was much different than it is in the civilian sector. For obvious reasons, you cannot have an outer containment vessel on a submarine or aircraft carrier.

The containment vessel is designed to hold the steam pressure if you have a release of primary coolant. From what I understand, they are usually designed to be able to contain the entire volume of coolant if it were to flash to steam, which is the 'worst case scenario' they are designed for. The reason they were venting pressure was so they did not have a steam explosion which could damage the containment building, then there would be a big problem as highly contaminated steam would be released plus the explosion could eject the control rods allowing the reactor power to spike, then the uncovered fuel could reach temperatures in excess of 1000 degrees melting the reactor vessel and even melt the concrete below it.

However, that is a worst case scenario. I don't think this is going to have impact that Chernobyl did for the simple fact that Chernobyl did not have a containment building. Their reactor was a flooded graphite reactor dug into the ground like a swimming pool. When it melted down, the graphite actually caught fire and burned with no containment. The smoke itself was highly radioactive. I might be proven wrong within the next few hours, but I don't think this will reach Chernobyl proportions of radiation release among all the reactors combined.
 
For clarification, the reactor has a containment vessel that is pressurized. Then you have an inner containment 'room' called the reactor room that contains the reactor, primary coolant pumps, pressurizer, and heat exchanger. Then you have a containment building. So there are 3 levels of containment.
 
That doesn't look very contained... sendai airport not surprisingly stopped reporting METARs just about the time of the quake. However the GFS forecast for the region shows light offshore winds(westerly) at the surface getting stronger with height... and this pattern prevails for a few days. So most of the radioactive debris goes offshore... in theory.
 
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