Japan Earthquake and Tsunami

[Puck it]

OK, I'll ask the dumbest question of the day. Could they not transport diesel fuel in somehow? I understand there is carnage all around, but somehow the hundreds of other operations staff were evacuated. <naive exposed>

I am not sure. You would think so, that makes me believe that the generators were also damaged. You think they could have pulled a ship up to off load since there appears to a break water and a dock.

 

[ctenidae]

Is there anything they can do to stop it over there or are they going to jsut keep heating up till they all blow? They have nowhere to ship the power they are producing as I understand it and they will just keep winding them selves up hotter and hotter till they explode. Am i correct?

Not having an offtake for the electricity doesn't have anything to do with the cores "heating up." The nuclear reaction in the core, simplisticly, does nothing but produce heat to boil water, producing steam. The amount of heat created is controlled in several ways, but if those methods aren't working, all you can do is try to cool things off with water. However, it's not a one-shot deal- the coolingw ater has to be in continuous supply. If the core is allowed to get too hot, you have a meltdown, generally with a massive release of radioactive material. Fortunately, it's unlikely it will degrade into a nuclear explosion, a la a bomb going off. Instead, it's like a massive pile of highly radioactive thermite. Hence the term "China Syndrome," based on the idea that an uncontrolled meltdown would send the core melting through the Earth all the way to China.

 

[drjeff]

I am not sure. You would think so, that makes me believe that the generators were also damaged. You think they could have pulled a ship up to off load since there appears to a break water and a dock.

The two potential issues I heard with that option was that #1 (and highly likely), there's so much debris both floating and submerged in the immediate shoreline water now that it's highly questionable that they could get a sizeable enough ship into the dock to make a difference and #2, if they could get a ship into the dock with enough pumping capacity to make a difference, is the piping system still intact enough to handle the sustain, high volume/pressure of water needed to make a difference??

 

[ctenidae]

I am not sure. You would think so, that makes me believe that the generators were also damaged. You think they could have pulled a ship up to off load since there appears to a break water and a dock.

I was thinking that, too, but it's pretty likely the fuel pumps, lines, and tanks are all damaged/full of water/full of sand/all of the above.

 

[tjf67]

The problem is that if the nuclear material has melted. There is no way to get material in to control the fission reaction. The boron rods aka control rods are spaced in between the fuel rods. These rods control the emitted particles off of the fuel that create the fission. If it is just a pool of molten fuel then there is no way to control it with fission limiting material. Cooling is the only way to keep things from going critical. The reaction will not explode but will self sustain and keep going until it melts through the vessel. This is bad needless to say. The "explosion" occurs when the material melts thorugh the vessel and concrete and then comes into contact with ground water. This is what will release the radiation to the atmosphere and get transported with the wind. The radiation from the reactor core is bad but very limited in area. The good thing is there appears to be no constant plume of steam emitting from the reactors which would mean a breach.

Does this help?

Yup make sense to me... Thanks

 

[Warp Daddy]

Puckster : keep the analysis fllowing -- its helpful to those of us who are /were :dunce: 's in Physics.

I appreciate the insights

 

[Puck it]

Fukushima Daini and Fukushima Daiichi are two separate plants about 7.5 miles apart.

According to its Wikipedia page (http://en.wikipedia.org/wiki/Fukushima_I_Nuclear_Power_Plant )Fukushima Daiichi has 6 active reactors with two more planned to be built. This facility is the one with the worst problems at the moment.

Fukushima Daini has 4 active reactors and has experience similar issues with cooling but there has yet to be any explosions reported there.

My point was I thought there was only 6 between the two sites until I heard about #4 and then did some more research. The plant to the north is having cooling problems also and is also the same type(BWR).

Individual units at the plant site: OnagawaOnagawa 1 BWR Japan OperableOnagawa 2 BWR Japan Operable

 

[Puck it]

I was thinking that, too, but it's pretty likely the fuel pumps, lines, and tanks are all damaged/full of water/full of sand/all of the above.

With regards to the tanks, the word is gone when look at the satelite images.

 

[from_the_NEK]

OK, I'll ask the dumbest question of the day. Could they not transport diesel fuel in somehow? I understand there is carnage all around, but somehow the hundreds of other operations staff were evacuated. <naive exposed>

It sounds like they got the diesel in to run the pumps but in the time it took to do so, the water levels inside the reactor dropped below the tops of the fuel rods. When this happened the super heated (500 degree) pressurized water around the rods begins to boil and makes returning a full water jacket around the rods difficult as it boils away on contact. The water pressure in the reactor chambers is very high to keep the water in a liquid state even at the high temps. If the water gets to 700 degrees, that is when water molecules start to break up and release Hydrogen.

At this point they should hook onto these drag them out to sea 100 miles and drop them in the Japan Trench where the water is 20,000ft deep. That would keep a lot of radiation out of the atmosphere but who knows what it would do to the ocean. :sad:

 

[Puck it]

Not having an offtake for the electricity doesn't have anything to do with the cores "heating up." The nuclear reaction in the core, simplisticly, does nothing but produce heat to boil water, producing steam. The amount of heat created is controlled in several ways, but if those methods aren't working, all you can do is try to cool things off with water. However, it's not a one-shot deal- the coolingw ater has to be in continuous supply. If the core is allowed to get too hot, you have a meltdown, generally with a massive release of radioactive material. Fortunately, it's unlikely it will degrade into a nuclear explosion, a la a bomb going off. Instead, it's like a massive pile of highly radioactive thermite. Hence the term "China Syndrome," based on the idea that an uncontrolled meltdown would send the core melting through the Earth all the way to China.

Until it hits a ground water source, then becomes an "explosion" of radioactive steam.

 

[ctenidae]

Until it hits a ground water source, then becomes an "explosion" of radioactive steam.

Which, in some ways, may be worse...

 

[Puck it]

It sounds like they got the diesel in to run the pumps but in the time it took to do so, the water levels inside the reactor dropped below the tops of the fuel rods. When this happened the super heated (500 degree) pressurized water around the rods begins to boil and makes returning a full water jacket around the rods difficult as it boils away on contact. The water pressure in the reactor chambers is very high to keep the water in a liquid state even at the high temps. If the water gets to 700 degrees, that is when water molecules start to break up and release Hydrogen.

At this point they should hook onto these drag them out to sea 100 miles and drop them in the Japan Trench where the water is 20,000ft deep. That would keep a lot of radiation out of the atmosphere but who knows what it would do to the ocean. :sad:

Very true about the fractionization of the water at those temps. Hooking onto a vessel in cased in concrete is not viable. The vessel is 6 inches thick and weighs several tons. Again, the radiation from the core itself is easily contained, if one can control the fission reaction. The sea water with the boric acid is a last ditch effort to control the reaction. It is the byproducts of the fission that will get transported to atmosphere if it comes into contact with the atmosphere such Cesium-137 and Strontium-90.

 

[Puck it]

Which, in some ways, may be worse...

Yes, it is. This is what happened in Chernobyl. The plume was the release of steam which contain the byproducts of the fissionable material and also operator error.

These reactors were immediatley scrammed which measn the boron rods were inserted immediately at the detection of the quake. The reaction shuts down very quickly but it is an exponential decay. There is latent heat that decays very slowly form the reaction though. From 100%, I think it decays to 6%(need to look up the number, it has been years since Nuke Physics) then that percentage of reaction left takes weeks to stop. And this remaining decay still needs cooling, if not then the material heats up and starts to self propgate creating more cooling problems until things melt and get to this situation.

 

[from_the_NEK]

Hooking onto a vessel in cased in concrete is not viable. The vessel is 6 inches thick and weighs several tons.

I know, the core vessel would become an immediate boat anchor if they tried to "pull it out to sea". I was just kind of playing on the rather dire situation.

Keep pumping the water boys...

It was mentioned above but does anyone have any idea how long these contanment vessel are designed to hold an uncontrolled melt down before it burns through the bottom?

Additionally, I'm not clear on what happens after the Fuel rods melt and the material falls to the bottom of the chamber away from the control rods. Can the build up of extreme heat cause the nuclear reaction resume without the control rods to halt it?

 

[Puck it]

Puckster : keep the analysis fllowing -- its helpful to those of us who are /were :dunce: 's in Physics.

I appreciate the insights

I hate to say this but right now I have a feeling that there is a lot of experimental physics going on there. We are going beyond where we have gone before. Too cliche!!!

 

[Warp Daddy]

I hate to say this but right now I have a feeling that there is a lot of experimental physics going on there. We are going beyond where we have gone before. Too cliche!!!

Frankly i assumed that much and certainly comprehend the ensuing difficulty of frankly TELLING the public TOO much at this point which could only add to the chaos , panic and despair that is no doubt setting in .

My deepest respect for those who are staying the course INSIDE the plants and sacrificing THEMSELVES for their fellow man .

 

[Puck it]

I know, the core vessel would become an immediate boat anchor if they tried to "pull it out to sea". I was just kind of playing on the rather dire situation.

Keep pumping the water boys...

It was mentioned above but does anyone have any idea how long these contanment vessel are designed to hold an uncontrolled melt down before it burns through the bottom?

It depends on the temperature in the core and how much water is cooling it. Stainless "plain old" melts @ 2750F. The core reaction can get to 2200F in very little time with no cooling. It then has about 6 feet of concrete around(secondary confinement). Hours wold be a good approximation for the SS vessel with no cooling and direct contact of the material to the vessel walls.

 

[Puck it]

Frankly i assumed that much and certainly comprehend the ensuing difficulty of frankly TELLING the public TOO much at this point which could only add to the chaos , panic and despair that is no doubt setting in .

My deepest respect for those who are staying the course INSIDE the plants and sacrificing THEMSELVES for their fellow man .

I am sure they are monitoring dose rates on the workers and cycling them out. All said I would not want to do it, but knowing the ramifications I think I would. I can only imagine what they are going through

During Loma Prieta in CA, I was working at Intel in a wafer fab and a memeber of the ERT (emegency repsonse team). No real radiation sources in fab except X-rays from our machines when running. However, there are a lot nasty arse chemcials that go into the chips that allow us to do this forum thing. Silane is one and ignites on contact with air. Phosphine also ignites and has TLV in the ppm's and Arsine which smells like garlic but if you smell it. It is too late, TLV is ppb. Boron trifluoride which produces HF in contact with air. This is just some of the ones in our tools. We had to sweep the fab for injuries and shut down the equipment. No major problems but the threat was there. Only a few machines had potential leaks.

 

[Morwax]

Very true about the fractionization of the water at those temps. Hooking onto a vessel in cased in concrete is not viable. The vessel is 6 inches thick and weighs several tons. Again, the radiation from the core itself is easily contained, if one can control the fission reaction. The sea water with the boric acid is a last ditch effort to control the reaction. It is the byproducts of the fission that will get transported to atmosphere if it comes into contact with the atmosphere such Cesium-137 and Strontium-90.

Im convinced you have no idea what you are talking about.
The fission reaction was shut down automaticaly after the quake and not whats creating the heat. Ive bit my tongue a bunch of times like when you stated the vessel was stainless steel. You may know some things but this subject is out of your league and your getting your google facts mixed up:beer:

 

[wa-loaf]

Im convinced you have no idea what you are talking about.
The fission reaction was shut down automaticaly after the quake and not whats creating the heat. Ive bit my tongue a bunch of times like when you stated the vessel was stainless steel. You may know some things but this subject is out of your league and your getting your google facts mixed up:beer:

Wow, there's a lot I don't agree with Puck it on. But I'd say you're the one being the moron here. And not to mention all around a-hole. If you've got something constructive to say on the subject please show us the light.