China Syndrome

It was a 1979 movie with Jane Fonda, Michael Dougla, and Jack Lemmon. I am sure many of us had seen the movie as I did see it myself. The movie was based on the hypothetical idea of an extreme result of a nuclear meltdown in which molten reactor core products breach the barriers below them and flow downwards through the floor of the containment building. The origin of the phrase, The China Syndrome, is the fictional idea that molten material from an American reactor could melt through the crust of the Earth and reach China.

Scientific explanation

The 'China Syndrome' refers to the most drastically severe meltdown a nuclear reactor could possibly achieve. In this case, the reactor would reach the highest level of supercriticality for a sustained period of time, resulting in the melting of its support infrastructure. The uranium in the core would behave in a similar manner to a delta-class fire, self-sustaining temperatures in excess of 2000°C. Since these temperatures would melt all materials around it, the reactor would sink due to gravity, effectively boring a hole through the reactor compartment's floor.

The China syndrome becomes fictional in the hypothesis of it boring a hole from the United States to China, or any other part of the world. Most obviously it is impossible because the Earth's gravity would only pull it towards the core of the planet and no further. Furthermore, were the molten reactor fuel to reach the planetary mantle, the actual environmental effect would likely be low; the radioactive material would disperse by convection throughout the mantle, which is in any case kept liquid by natural nuclear decay. However, it is likely that the uranium core would not exceed more than 10 meters of 'boring' due to natural passive safety. The surrounding ground beneath the reactor would absorb the heat and transfer its conductivity to the surrounding area, thus preventing the ground directly beneath the core from 'melting'.

What About it now ??

According to the latest news tonight, the hypothetical movie story is actually happening in the northern Japan hit by the giant tsumani !!

As the cooling system failed by the earthquake, the reactor temperature had been dangerously rising. As a stop-gap measure, they were trying to cool the reactor by sea water but obviously it was not efficient enough for the last two days. No one could be there to check this out visually or mechanically.

This evening, according to Japan's chief Cabinet secretary, "We are assuming that a meltdown has occurred" at a quake-damaged nuclear reactor."
(by CNN News)

What has been happening in Japan?

_Temperature in the reactor vessel apparently kept rising, heating the zirconium cladding that makes up the fuel rod casings. Once the zirconium reached 2,200 degrees Fahrenheit (1,200 Celsius), it reacted with the water, becoming zirconium oxide and hydrogen.

_When the hydrogen-filled steam was vented from the reactor vessel, the hydrogen reacted with oxygen, either in the air or water outside the vessel, and exploded.

A similar "hydrogen bubble" had concerned officials at the 1979 Three Mile Island nuclear disaster in Pennsylvania until it dissipated.

If the temperature inside the Fukushima reactor vessel continued to rise even more — to roughly 4,000 degrees Fahrenheit (2,200 Celsius) — then the uranium fuel pellets would start to melt.

According to experts interviewed by The Associated Press, any melted fuel would eat through the bottom of the reactor vessel. Next, it would eat through the floor of the already-damaged containment building. At that point, the uranium and dangerous byproducts would start escaping into the environment.

At some point in the process, the walls of the reactor vessel — 6 inches (15 centimeters) of stainless steel — would melt into a lava-like pile, slump into any remaining water on the floor, and potentially cause an explosion much bigger than the one caused by the hydrogen. Such an explosion would enhance the spread of radioactive contaminants.

If the reactor core became exposed to the external environment, officials would likely began pouring cement and sand over the entire facility, as was done at the 1986 Chernobyl nuclear accident in the Ukraine, Peter Bradford, a former commissioner of the U.S. Nuclear Regulatory Commission, said in a briefing for reporters.

At that point, Bradford added, "many first responders would die."

Note: The death will be by radiation exposure. The same happened in the Chernobyl nuclear accident that occurred on 26 April 1986. Some Japanese helicopter pilots have to make "kamikaze" attacks to the remnant of the reactor pit in order to fill the void with concrete. In Chernobyl, they hadn't quite realistically known the chance of death. But, now, they know. Someone has to volunteer for the job.

Then What ??

Even the fully-blown China Syndrome will not, hopefully, affect us very much in America except some radiation contamination of our air. Most of the damage will be in Japan to the immediate vicinity of the nuclear reactor. For us, it's nothing to lose our sleep about tonight.
We will be hearing more in the morning of Sunday when we wake up.


Composed by SNUMA WM by combining news stories available this evening.
11:00PM, March 12, 2011