From bad to worse to cataclysmic. Lord have mercy.
My goodness if these reactors go the tsunami will be nothing compared to the devastation these plants could cause. Is the radiation at lethal doses yet inside th reactors? I hear its like 1000 times above normal and climbing.
Prayers for Japan.
"That's as a last resort, and we have not reached that stage yet," Kakizaki added.
And now it seems that it might be hitting the fan at these nuke plants. The Japanese have been good friends for 60 years...it is heartbreaking.
I really only understand enough about this technology...
but did this problem happen when the earthquake struck and they are only now trickling out information about the seriousness of the situation?
The news coming out of Japan just gets worse. May God help them.
These are very precautionary evacuations and if there was a chance of a Japanese version of the China Syndrome, they would be evacuating a lot more area than just 10 miles around these plants.
Think about Chernobyl. The reason it continues to be so horrible is that there was absolutely no containment around the reactor, so when it blew it spewed directly into the atmosphere for weeks until they could snuff it.
The Japanese nuclear generation plants are state of the art with many backup systems to prevent a major accident; and I define “major” as being on the level of a Chernobyl. They are not even close anywhere in Japan.
Most Japanese are atheists, but I will say a prayer for them anyway.
Prayers up for Japan.
Spread the word.
Radiation detected at a central control unit at Tokyo Electric Power Co's No.1 reactor at Fukushima Daiichi plant is not at a level that would require workers at the plant to evacuate, a trade ministry official said on Saturday.
The radiation at the control unit has risen to about 1,000 times the normal level, the official said..--Reporting by Osamu Tsukimori
The MSM is good at sensationalizing. Fear is a powerful tool.
Yes, this is tragic..BUT I have faith in Japan, as they are well aware they are in a high stress location, thus they build on their real estate accordingly. I am sure they know what they are doing with backups for backups. The Anti-nuke-energy crowd will play off this and are.
"The United States has transported coolant to a Japanese nuclear plant affected by a massive earthquake and will continue to assist Japan, Secretary of State Hillary Clinton said on Friday. "We just had our Air Force assets in Japan transport some really important coolant to one of the nuclear plants," Clinton said at a meeting of the President's Export Council.
"You know Japan is very reliant on nuclear power and they have very high engineering standards but one of their plants came under a lot of stress with the earthquake and didn't have enough coolant," Clinton said
These reactors have multiple, layered safety systems for just such an eventuality. Hope and pray for the best. There is enough known horror for the time being.
Not to sound callous but if they’re only evacuating a 2M radius this is under control. Serious, but within containment.
Prayers up nonetheless.
---------
I’ve worked in the US nuclear industry for 30+ years and for 18 years I was a licensed senior reactor operator/control room supervisor on a boiling water reactor (BWR) similar to the Fukushima plant. I helped write the emergency procedure guidelines that are used at US BWRs. There is a great deal of information flying around that just does not make sense. There just seems to be no detailed technical information getting out to the public on this. At the risk of over simplifying the system, a BWR is like a giant pot of boiling water. Regular light water, not heavy water, goes through the reactor, is heated by the splitting of uranium atoms, turns to steam and spins a turbine-generator to make electricity. The steam is condensed back to water and pumped back into the reactor to continue the cycle.
There are 3 basic barriers to the release of radiation: the metal clad that encases the uranium fuel, the reactor pressure vessel, and the containment. If 2 of these 3 are compromised, and the third is in jeopardy, US plants will advise shelter or evacuation of nearby residents.
The reactor operates at a normal pressure of about 1000 psig. During an earthquake of this magnitude, the reactor would be expected to automatically shut down (called a reactor scram). Control rods are hydraulically driven into the core in less than 7 seconds. I do not know if this took place but if it did not, we’d probably hear about it because it would be such a big deal. Even with rods inserted, the reactor continues to produce heat equivalent to about 3% of its full power level. This is not the same as taking a pot off the stove and letting it cool. There are still some atoms splitting and fission products decaying that produce heat. This drops off slowly and is why there needs to be layers of redundant cooling with backup power. During such an earthquake, power from outside the plant would not be expected to be available.
The plants have several back up diesel generators (locomotive style engines) that supply power to motor driven cooling systems that will supply high flow of water up to about 300 psig.. There are also steam driven systems to supply cooling water up to 1100 psig. There are also pressure relief systems that active at about 1100 psig. If reactor pressure gets too high, relief valves open and discharge steam to a water filled pool inside the containment.
Here are some information being reported that does not make sense. Reports that the pressure is 1.5 times normal; incorrect. There are at least 10 relief valves and any one can handle the energy after a plant shut down. CNN reports the US military has flown coolant to the site, but the coolant they use is regular water; I can’t imagine why the US would need to fly in coolant.
Right now I’d want to know a few things.
Are all rods fully inserted? What is the water level in the reactor? It’s normally about 12 feet above the top of the fuel. What injection systems are available? What is the reactor pressure? What is the status of containment?
Based on limited information, this is what I think might happen:
Earthquake hits, high vibration on the main turbine automatically trips the turbine by rapidly closing stop valves. Reactor automatically shuts down (scrams) all rods go in. Earthquake disrupts off site power to the plant and back up diesel generators should have started, maybe they did not. Main sources of water to the reactor are not available. If there is no pipe break off of the reactor, the pressure will slowly increase. After about an hour, a relief valve(1 of about 10) will open at about 1100 psig and drop pressure to about 1080. The steam is sent to a pool of water called a suppression pool in the containment that condenses the steam. This valve will cycle open and close every 5-10 minutes. Operators would use a small steam driven turbine (RCIC) to supply water at high pressure to the reactor under these circumstances for several hours. You can sit like this a long time, hot and at 1000 psig it’s no big deal as long as water covers the fuel in the reactor pressure vessel. If that turbine is not available, there is a larger steam driven turbine (HPCI) that supplies more water meant to provide make up if there was a pipe break.
If neither of these systems is available, the relief valve will continue to cycle and reactor water level will slowly drop. At some point before the water level lowers to the point of uncovering the fuel, all the relief valves would be open (ADS) and pressure would be reduced to below 300 psig to allow the low pressure but high flow systems (CS & LPCI) to restore water level and cooling. These pumps however, need electricity, like from the diesel generators, to run. If things get this far but there is no injection, in US plants there are things like diesel fire pumps that can be tied in to provide alternate sources of water. I’m not sure if they are set up to do this in Japan. Without cooling, eventually the fuel temperature will exceed 2200 deg F and the clad will melt. Fission products that are highly radioactive will get dispersed into the reactor vessel. If there is a pipe break or relief valve open, those fission fragments get dispersed through containment.
I’m going to throw out a question for those of you who are knowledgeable about the bond market (I freely admit that I don’t know diddly):
What happens, once Japan determines that she has a huge need for cash for cleanup and rebuilding ruined areas, and someone suggests they sell off all or part of the approx. $700 billion in US treasury bonds?
That may be a silly thing to worry about but I haven’t heard it mentioned so far. To me, it is a legitimate thing to worry about given Japan’s monetary needs and our exposure.
Serious answer, anyone?
Bad day.
If you start with a penny, a 1000-fold increase in your wealth does not make you rich in any way.
God be with Japan during this time of need.
As a professional engineer, it sounds like the pumps were damaged.
It seems to me not enough redundacy was built in.
Bookmark for later.