Japan Does Not Face Another Chernobyl
The core of a nuclear reactor operates at about 550 degrees Fahrenheit, well below the temperature of a coal furnace and only slightly hotter than a kitchen oven. If anything unusual occurs, the control rods immediately drop, shutting off the nuclear reaction. You can't have a "runaway reactor," nor can a reactor explode like a nuclear bomb. A commercial reactor is to a bomb what Vaseline is to napalm. Although both are made from petroleum jelly, only one of them has potentially explosive material.
Once the reactor has shut down, there remains "decay heat" from traces of other radioactive isotopes. This can take more than a week to cool down, and the rods must be continually bathed in cooling waters to keep them from overheating.
On all Generation II reactors—the ones currently in operation—the cooling water is circulated by electric pumps. The new Generation III reactors such as the AP1000 have a simplified "passive" cooling system where the water circulates by natural convection with no pumping required.
If the pumps are knocked out in a Generation II reactor—as they were at Fukushima Daiichi by the tsunami—the water in the cooling system can overheat and evaporate. The resulting steam increases internal pressure that must be vented. There was a small release of radioactive steam at Three Mile Island in 1979, and there have also been a few releases at Fukushima Daiichi. These produce radiation at about the level of one dental X-ray in the immediate vicinity and quickly dissipate.
If the coolant continues to evaporate, the water level can fall below the level of the fuel rods, exposing them. This will cause a meltdown, meaning the fuel rods melt to the bottom of the steel pressure vessel.So, there will be no Chernobyl, no nuclear explosion and no release of very dangerous levels of radiation. So one would ask why the Democrats are calling for a moratorium on Nuclear Plant contruction (considering none are being built in the US):
Early speculation was that in a case like this the fuel might continue melting right through the steel and perhaps even through the concrete containment structure—the so-called China syndrome, where the fuel would melt all the way to China. But Three Mile Island proved this doesn't happen. The melted fuel rods simply aren't hot enough to melt steel or concrete.
The decay heat must still be absorbed, however, and as a last-ditch effort the emergency core cooling system can be activated to flood the entire containment structure with water. This will do considerable damage to the reactor but will prevent any further steam releases. The Japanese have now reportedly done this using seawater in at least two of the troubled reactors. These reactors will never be restarted.
None of this amounts to "another Chernobyl." The Chernobyl reactor had two crucial design flaws. First, it used graphite (carbon) instead of water to "moderate" the neutrons, which makes possible the nuclear reaction. The graphite caught fire in April 1986 and burned for four days. Water does not catch fire.
Second, Chernobyl had no containment structure. When the graphite caught fire, it spouted a plume of radioactive smoke that spread across the globe. A containment structure would have both smothered the fire and contained the radioactivity.
If a meltdown does occur in Japan, it will be a disaster for the Tokyo Electric Power Company but not for the general public. Whatever steam releases occur will have a negligible impact. Researchers have spent 30 years trying to find health effects from the steam releases at Three Mile Island and have come up with nothing. With all the death, devastation and disease now threatening tens of thousands in Japan, it is trivializing and almost obscene to spend so much time worrying about damage to a nuclear reactor.
What the Japanese earthquake has proved is that even the oldest containment structures can withstand the impact of one of the largest earthquakes in recorded history. The problem has been with the electrical pumps required to operate the cooling system. It would be tragic if the result of the Japanese accident were to prevent development of Generation III reactors, which eliminate this design flaw.
Should the US ‘put the brakes’ on nuclear? Some Dems think so
Some U.S. lawmakers are looking to “put the brakes” on building new nuclear power plants after witnessing the crisis at several Japanese reactors that were rocked by Friday’s massive earthquake and tsunami.
Sen. Joe Lieberman (I-Conn.) called for a temporary moratorium on the construction of nuclear power plants in the United States following the Japanese quake, which damaged two reactors at a nuclear facility in the country's northeast.
"The reality is that we're watching something unfold," he said on CBS' "Face the Nation." "I think it calls on us here in the U.S. naturally – not to stop building nuclear power plants – but to put the brakes on right now until we understand the ramifications of what's happened in Japan."
"I've been a big supporter of nuclear power because it's domestic, it's ours and it's clean," Lieberman said. "I don't want to stop the building of nuclear power plants, but I think we've got to kind of quietly, quickly put the brakes on until we can absorb what has happened in Japan as a result of the earthquake and the tsunami and then see what more, if anything, we can demand of the new power plants that are coming online."
Sen. Chuck Schumer (D-N.Y.) said he, too, was watching the dangers at Japan’s nuclear plants and considering the domestic implications.
"I'm still willing to look at nuclear, but it has to be done safely and carefully,” he said on NBC's "Meet the Press." "Bottom line is we do have to free ourselves from our dependence on foreign oil."
Rep. Edward Markey of Massachusetts, the senior Democrat on the House Natural Resources Committee, warned Saturday that the U.S. is vulnerable to the same type of nuclear accident.
“I am also struck by the fact that the tragic events now unfolding in Japan could very easily occur in the United States,” Markey said. “What is happening in Japan right now shows that a severe accident at a nuclear power plant can happen here."
Markey called on the Obama administration and the Nuclear Regulatory Commission to consider the implementation of several policy changes in light of the disaster.
Of course this is the typical "knee jerk reaction" that the Democrats use all the time during a crisis. Which brings us to this article:
Nuclear Facts to Remember While Following Japan
The cable news networks and newspapers are filled with frightening headlines like “Radioactive Releases in Japan Could Last Months” that will aid Markey’s anti-nuclear crusade. But the reality is far removed from the hype. Here are some cold hard facts to keep in mind as news continues to come in from Japan:So, let's wait and see what happens in Japan in relation to the Nuclear Reactors, but at the same time cooler heads should prevail. We don't need a moratorium on something that we are not currently building in the first place.
•The low levels of radiation currently being released will likely have no biological or environmental impact. Humans are constantly exposed to background radiation that likely exceeds that being released.
•The Chernobyl disaster was caused by an inherent design problem and communist operator error that is not present at any of the nuclear plants in Japan.
•There were no health impacts from any of the radiation exposure at Three Mile Island.
•The Nuclear Regulatory Commission does not need to regulate more in response to this. It already regulates enough.
•The plant in trouble in Japan is over 40 years old. Today’s designs are far more advanced.
•No one has ever been injured, much less killed, as a result of commercial nuclear power in the U.S.
The danger that Japanese engineers are currently grappling with should not be minimized: what is happening right now with Japan’s reactors could lead to a meltdown and significant release of radiation. You could also get hit by a car on your way to work today. But that is not what is likely to occur. What is likely to occur is that Japanese officials will continue to operate professionally and oversee the order cooling of these plants.
Events unfolding in Japan ought to have no impact on the current U.S. reactor fleet or future plans to expand that fleet. The Nuclear Regulatory Commission does not need to regulate more in response to this. We need to remember that nuke plants are privately owned and that their owners have every incentive to maintain safe operations. The government’s role should simply be to set and enforce fair, efficient, and effective safety and environmental standards and allow private industry to meet them. Anti-nuke crusaders like Markey make this balance impossible. If the risk of nuclear power is too great, investors will put their money somewhere else.