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There already is Q and A thread about Japan earthquake, but not about nuclear crisis. This thread is about nuclear crisis.
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Media Hysteria?

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When quake and tsunami hit, newspapers realized that this would be a multidimensional crisis. There is the heartbreaking human story, as the residents of the northeast coast try to rebuild their lives. Those stories have been told with great sympathy in articles. And then, there are the broader issues.

But media also realized that the nuclear crisis occuring at the Fukushima plant was unlike any we have seen in history. While damage from the quake and tsunami was visible, the nuclear impact, it could affect far larger population of Japan and neighboring countries. Sadly, that is exactly what is happening.

Health Risks

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This is frustrating for all, because the answer depends in part on the prevailing winds. However, experts strongly doubt that there will be any significant risk on the West Coast, and say there is no reason to take the potassium iodide unless high levels of radioactive iodine develop. In addition, about 98 percent of a person’s dose comes from drinking contaminated milk, and if fallout were to reach here most people could protect themselves by not drinking milk.

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The only risk would be if someone contaminated at the site came into your home wearing clothing full of radioactive fallout. Otherwise, you are O.K.

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An article said that the Japanese government has “taken precautions that should prevent the accident from becoming another Chernobyl, even if additional radiation is released.”



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People near the plant have been evacuated. The ones being warned to stay inside are miles and miles away. There's some dispersion of the clouds and levels at a distance should decrease, so the risk decreases too and staying inside, seems like a rdecent precaution.

Crisis at the Reactors

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The Japanese authorities have provided few details of how they are pumping water into the three stricken reactors. Nuclear engineers and executives say that the Japanese are propably using several pumper engine firetrucks in a row. This technique is sometimes used in high-rise firefighting, when the goal is to maximize the flow and pressure of the water. At the Fukushima plant, maximum pressure is needed to force water into overheated reactors.

The pumping process has been full of problems. Temperature and pressure climbed in the reactor as a result may have contributed to damage to the fuel rods and to an explosion.

Japanese officials have looked for other options. One idea under consideration has been to use helicopters to drop water. But helicopter crews received heavy doses of radiation from the smoke.

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The sea water is turning to steam. The reactor is still so hot that the sea water they are pumping in is just intended to replace the amount that boils off and they're just managing to keep the reactor covered with water.

In the reactors that have had fuel rod exposure, the steam would be contaminated with radioactive elements, which has been exposed because of cracking of the zirconium. The contaminated steam leaves the reactor tank and enters the containment structure. To avoid a pressure buildup, the containment structure must be vented periodically, resulting in the release of radioactivity to the environment.

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The reactors at the Fukushima plant are shut down, meaning that the nuclear chain reaction has been aborted. That happened automatically when the earthquake struck.

The reactors were very hot and it takes a while to remove that heat. In addition even though the chain reaction is stopped, heat is still generated in the fuel. This heat is why they need to keep pumping water into the reactor core, exposing the fuel rods. And if the fuel rods are exposed, even for a short time, they become damaged and radioactivity is released.

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Experts differ on the impact of a full meltdown of the nuclear fuel at reactors. Some say that the melted fuel would be unlikely to burn through the walls of the reactor vessel. Others say that a burn-through would happen, with the melted fuel then falling to the floor of the containment structure. What would happen next is a subject of debate too. Some experts think the fuel would not progress far before it started to cool. Others say that it could reach the walls of the containment structure and damage it. Some experts are worried that steam explosions might completely destroy the containment structure.

Even if melted fuel remains in the reactor vessel, radiation will escape through vents into the containment structure. And the containment structures in at least two of the reactor buildings appear to have been damaged.

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It's not clear yet, but the answer appears to lie in the backup cooling systems. At Fukushima, the plants survived the earthquake, but the backup cooling was wiped out by the tsunami. The question of why one plant survived so well and another did not will be the focus of many questions as journalists try to reconstruct events.

A Question of Human Error

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When a fire pump ran out of fuel and shut down outside Reactor No. 2 on Monday night, that was human error. But it is not clear that the rest of the difficulties are related to human error.

There isn't confirmation that a valve was improperly left closed, and/or the valves have been under a lot of strain on overheated reactors. Some Western nuclear engineers have wondered if the Japanese waited too long to begin pumping in seawater and boric acid. But the Japanese technicians faced a tough problem in figuring out how much boric acid to use and how to move the seawater after the tsunami.

Chernobyl and Three Mile Island

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The international agreement is that eventually, reactor wastes will have to be buried. The United States plans to do that with all spent reactor fuel. It is sitting in containers at the Idaho National Laboratory, near Idaho Springs.

In the shorter term, the cores from Fukushima are also likely to go into containers. Such “dry cask storage” can keep reactor wastes isolated for decades, with minimal requirements for inspection, and no moving parts.

The Japanese “recycle” some of their fuel. That could also happen to the reactor core rubble from Fukushima. But those wastes, too, will probably eventually be buried.

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At Three Mile Island, the fuel was cleaned out and shipped off site and the reactor vessel was left to wait until a companion plant was ready for retirement. At that point, probably both will be torn down just as other old reactors. The Fukushima accident is not over, but unless it gets a lot worse, defueling is more likely than entombment, because someone is likely to want to reuse the site.

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There are two potential mechanisms. One is to pump in cold water and wait for it to boil off, and then release the steam. The other is that the spent fuel pools are heating up. If they boil dry, there is a theory that the fuel could get hot enough so that its metal cladding an it could catch fire. A fire would produce enough energy to lift radioactive contaminants into the air.

At Chernobyl, the graphite burned and provided enough energy to lift the radioactive material into the jet stream. It isn't clear whether a significant portion of the wastes from Fukushima could rise that high. With a little luck, material could stay in the lower atmosphere and be washed out by rainstorms over the Pacific.

Nuclear Policy

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Reactors are attractive to Japan because the country has barely any fossil fuels, which together make up 70 percent of American power generation or any significant oil supply.

Almost all of Japan’s civil infrastructure is built with earthquakes and tsunamis in mind. The country is ringed with tsunami barriers. But this earthquake was the largest in recorded (Japan's) history and the tsunami was higher than the planners assumed. And along with killing thousands of people, it swamped the reactors.

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That's an interesting policy question that came up, during last year’s oil spill as well. Nuclear power plants are subject to federal regulation; the question you are raising is whether safety would be better if they were state-owned. The answer to that question is not clear. And NASA no longer has a monopoly on space flight: One key element of the Obama administration’s space strategy is to encourage more private firms to enter the fray.


I left out one question, becouse it was question related to NY Times.
Please, don't flame me for copy pasting, becouse editing and shortening text took me a lot of time.
Thanks and I hope this answered your questions about this nuclear crisis.

I've already made a thread about this.
It was the shoutbox notice.
Here's the link: You must login or register to view this content.

The thread was made for a discussion about the primary and secondary effects of the earthquake, and the nuclear crisis falls into one of them. I would post this thread in a reply in it :y:

But this is just about Nuclear Crisis and possible effects it can cause, and your Q and A was generally about eartquake so it's different.

I hope the wind's dont come to ireland :L

Wow.Looks like I wont have to worry too much here in Cali.

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