Japanese Tsunami

[Freiwillige]

Good news on the horizon at last!

http://news.yahoo.com/s/ap/as_japan_earthquake

Power lines are being routed and are almost ready to bring power back to the plant.

[Type941]

Originally Posted by UnderseaLcpl

Here's a question: Why weren't the control rods designed to simply drop into the core in the event of a power failure to stop the reaction?

I'm not an expert on this stuff, but I have what would probably be best described as a casual interest in nuclear power-generation technology. From what I understand, a full application of control rods should be enough to stop any reaction the plant is capable of generating. If that is correct, why weren't the control rods released the moment the power failed? Feel free to stop me right here if I've got something wrong.

In any case, I spoke to a friend of mine who works in the BNSF corporate office the other day and she said she wasn't surprised by what happened to the Japanese reactors because many of their systems were designed by General Electric. To clarify, BNSF Railways Inc. does a lot of business with GE. She told me that GE has a history, in recent years, of designing failsafes that aren't really failsafes because they like to cut corners at the expense of quality.

Her assumption was that the Japanese reactor failsafes were probably a lot like the failsafes they installed on the engines of our DASH-9 CE-44W locomotives to prevent plasma arcing in the event of a current reversal; which is to say that they rely upon the other systems in the cheapest, most basic system they could design to power the failsafes, which seem to have been "tacked-on" after the original design was completed.

In our case, we've suffered some damage to locomotive engines because the computer that is supposed to prevent the electronically-relayed command to the generators to reverse direction, and therefore current flow (locos use DC power), doesn't always function properly. Under some emergency circumstances, it will allow a sudden reversal of current, which fries the hell out of the motors.

I wonder if this situation with the Japanese nukes is indicative of faulty GE engineering to cut corners in the same way - utilizing existing systems to power failsafes. It seems to me that a simple pneumatic or hydraulic system that would activate in the absence of current would be sufficient to propel the control rods into the reaction chamber, much as airbrakes on trains will apply in the absence of air pressure.

Thoughts?

Rods dropped fine. The thing is, the fuel reaction is going to go on for a long time, the rods don't kill it, they just take it down to a marginal level. So that stuff is easy to cool off in normal environment and is later stored in pools when used up (hence, the whole drama of fires in the pool with used fuel - see they still need to store it). There are safer way store it, in dry conditions I heard but don't know much more about it. The temperatures are much lower of course and so it's not that big of an issue as with hot reactor.

This chart perhaps explains it better for you - take a look:


It is about .5% of reactor power now.

More info here (scroll to decay heat article): http://mitnse.com/

[Freiwillige]

And now the bad news.

http://news.yahoo.com/s/ap/20110316/...ake_spent_fuel

[papa_smurf]

From BBC News:

1. 2038: Experts warn that if radiation levels become too high, workers at the plant would not only be prevented from approaching reactor 4's spent fuel pond, but also the adjacent reactors, which also have malfunctioning cooling systems.
   
   

[Type941]

Originally Posted by Freiwillige

And now the bad news.

http://news.yahoo.com/s/ap/20110316/...ake_spent_fuel

yet TEPCO is in denial and saying all is OK in the pool. how you explain that. I trust the americans more as they're ordering much wider exclusion alrady of 50 miles. seems it's a matter of time now - look at the pictures, they are just one by one starting to look like a SimSity housing project gone bad.

[Oberon]

I must admit, TEPCO has been quite misleading, I understand they don't want to cause a panic but sometimes less information is more damaging than more.

At the moment TEPCO kinda looks like this to me:



"Ok, nothing to see here, move along please..."

[Skybird]

By archgitectural layout, the pools for old rods are stored not on ground level, but in elevated, uncovered bassins comparing to 5th and 6th floor. And the roofs went ablast and there was plenty of steam, and very big explosions with huge shockwaves doing additonal damage to the interior. I have big problems with believing anybody trying to tell me that the pools are still filled with water. I take it for granted that the rods in there are exposed and heating up. On TV they said the burnt rods need to lay dry for 48 hours before they start to ignite themselves.

They lost it. It's time to think about how to contain the site's radiation with a sarcophage. And how to maintain that hull for the coming millenia. Chernobyl took less than 15 years before the first fractures and splits in the outer hull were discovered.

[ASWnut101]

Originally Posted by UnderseaLcpl

Here's a question: Why weren't the control rods designed to simply drop into the core in the event of a power failure to stop the reaction?

I'm not an expert on this stuff, but I have what would probably be best described as a casual interest in nuclear power-generation technology. From what I understand, a full application of control rods should be enough to stop any reaction the plant is capable of generating. If that is correct, why weren't the control rods released the moment the power failed? Feel free to stop me right here if I've got something wrong.

Yeah, the rods are hydraulically or (in emergencies that disabled the hydros) steam driven into the core from below to scram it. The reactors all scrammed as expected, it's just the decay heat that has been causing all of these problems.

Most other reactor designs uses rods that are attached to electromagnets. If the power goes out, gravity pulls them into the core.

In any case, I spoke to a friend of mine who works in the BNSF corporate office the other day and she said she wasn't surprised by what happened to the Japanese reactors because many of their systems were designed by General Electric. To clarify, BNSF Railways Inc. does a lot of business with GE. She told me that GE has a history, in recent years, of designing failsafes that aren't really failsafes because they like to cut corners at the expense of quality.

Her assumption was that the Japanese reactor failsafes were probably a lot like the failsafes they installed on the engines of our DASH-9 CE-44W locomotives to prevent plasma arcing in the event of a current reversal; which is to say that they rely upon the other systems in the cheapest, most basic system they could design to power the failsafes, which seem to have been "tacked-on" after the original design was completed.

In our case, we've suffered some damage to locomotive engines because the computer that is supposed to prevent the electronically-relayed command to the generators to reverse direction, and therefore current flow (locos use DC power), doesn't always function properly. Under some emergency circumstances, it will allow a sudden reversal of current, which fries the hell out of the motors.

I wonder if this situation with the Japanese nukes is indicative of faulty GE engineering to cut corners in the same way - utilizing existing systems to power failsafes. It seems to me that a simple pneumatic or hydraulic system that would activate in the absence of current would be sufficient to propel the control rods into the reaction chamber, much as airbrakes on trains will apply in the absence of air pressure.

Thoughts?

While I'm not going to deny that corners may have been cut (because I can't), the Fukushima Dai-ichi plant is around 40 years old. It was built back in the heyday when we weren't as concerned (or at least aware) about the safety issues. Modern designs have actually drastically improved the safety and reliability of BWRs, culminating in the design of the modern ABWR (Advanced Boiling Water Reactor).

This tragedy has actually raised some questions about the fundamental design of the reactor's safety systems. It's kind of technical, but in a (large?) nutshell, when designing the ABWRs, engineers got together and tried to think up the worst possible series of events that could happen to the reactor. What they came up with is called a DBA, or Design Basis Accident. However, chemical explosions and actual damage to the emergency subsystems of the reactor were never included in the DBA scenario, so it will be interesting to see how the designs change and what they do with the modern BWRs already installed to make sure something like this wont happen again.

look at the pictures, they are just one by one starting to look like a SimSity housing project gone bad.

That's horrible...but it made me laugh anyway

[Skybird]

Originally Posted by Oberon

I must admit, TEPCO has been quite misleading, I understand they don't want to cause a panic but sometimes less information is more damaging than more.

Tepco is a cheater. Since years they are engaged in long chain of scandals, deceptions, coverups, lies and more lies. Unfortunately, there is probably no othert country in the world where the nuclear lobby has lobbied so intensely and successfully for political influence, like in Japan.

It's pretty much a Mafia. But then, much of the economic structure of Japan is. Especially Americans often claim they successfully turned Japan into a democracy after WWII. But that they can only claim because they never have loked close enough. The Japanese econolmy, and thus its political system, is being run by very different mechanisms and powerstructures than that you gain by democratic legitimation processes and open market economy.

This does not mean that Western corporations do not successfully run efforts to erode the democratic sysxtem, too. I only say energy and oil companies, Monsanto, Halliburton, and so many others. And Europe - shares the vision of wanting a dioctaorship, too. The decison-making power-structures in the EU more and more remind me of the way corrupt, rotten cadres ran the former GDR and the USSR.

[Catfish]

Originally Posted by Skybird

... there is probably no othert country in the world where the nuclear lobby has lobbied so intensely and successfully for political influence, like in Japan.

It's pretty much a Mafia. But then, much of the economic structure of Japan is. Especially Americans often claim they successfully turned Japan into a democracy after WWII. But that they can only claim because they never have loked close enough. ...

Why, the whole US conservative leadership and especially the CIA is the mafia

[Type941]

I guess here's the rub. If reactor operates at full power, the fuel element lasts like 3 years before being put into that nice "safe pool". The fact that reactor scrammed, means that the operating power is down to less than 1% in matter of days, and dropped to 6% in about 1 second. So now's the b.tch of a situation - this energy is still all there. So if you had 3 years to spend it, now you got 100. So effectively this crap has to be either safely stored in water OR it goes kaboom and releases all this nuclear energy in one blast. Can it happen? I don't know but they are suggesting it this US speech they made just now. Since there is many of them together, they melt, etc. And reactor 3 has Plutonium as well which makes it the most dangerous.

Really, this is bad, very bad, and very very bad. I think it's going to blow up and we'll have a massive fallout for 200-300 km. And Japan is done as a power for long long time. We can also expect another recession globally as a result because let's face it, fuel prices doubling through speculators will not help the consumers already full in debt, while increase tension further because now countries like Iran, Russia, and other oil rich nations get a chance to REALLY show what money can do.

My only hope, is that from this: 1) New ways of dealing with nuclear disaster are learned 2) people acutally survive it better than Chernobyl 3) renewable's research steps up a notch, lead this time by government and not private companies which aren't motivated enough it seems and 4) the world calms the fak down, because lately the whole political world feels like this Daichi powerplant.

If this was a movie, in a last possible moment some engineer woudl throw some yogurt/baby panda/ipod at the reactor and that would stop it completely and voila we have found a strange way of fighting radiation and world is saved. But as people who follow dating advice from movies know, movies and real life just ain't the same thing.

[XabbaRus]

OK it can't go kaboom, no nuclear explosion.

It has to be kept cool as they still generate heat, and they should be kept separate.

Now maybe corners have been cut and there are lessons to be learnt, but all this worlwide panic and condemnation of nuclear power is ridiculous.

Please give me viable green economically effective alternatives.

Wind power...cost per/MW generated to install windpower is not cost effective, in the UK the government pays subsidies to power firms to install and run them. Wave power is immature and again ineffective. Hydro is a viable alternative for the UK, but as soon as you start damming valleys people complain about drowning the rabbits. Nuclear does not automatically mean dangerous....

[Type941]

Originally Posted by XabbaRus

OK it can't go kaboom, no nuclear explosion.

It has to be kept cool as they still generate heat, and they should be kept separate.

Now maybe corners have been cut and there are lessons to be learnt, but all this worlwide panic and condemnation of nuclear power is ridiculous.

Please give me viable green economically effective alternatives.

Wind power...cost per/MW generated to install windpower is not cost effective, in the UK the government pays subsidies to power firms to install and run them. Wave power is immature and again ineffective. Hydro is a viable alternative for the UK, but as soon as you start damming valleys people complain about drowning the rabbits. Nuclear does not automatically mean dangerous....

Wind is dead end, i give you that - it's the base load problem. Germany blackouts few years back showed this VERY well.

It's not a nuclear explosion but an explosion from contact with something explosive, like may be too much water at too hot fuel? I don't know but isn't that the danger? The explosion of any kind putting all this radioctive crap into the air and spreading that where wind blows?

[Betonov]

So effectively this crap has to be either safely stored in water OR it goes kaboom and releases all this nuclear energy in one blast. Can it happen?

It won't go off like a nuclear bomb. You need to compress the uranium and then fire a neutron into the mass to start a chain reaction, can't happen in fuel rods.
But it can go kaboom. The heat would generate gases that would biuld up pressure and one day go kaboom like a baloon, or some chemical reaction generating flammable gases that would also go kaboom

[Pablo]

Originally Posted by XabbaRus

OK it can't go kaboom, no nuclear explosion.

It has to be kept cool as they still generate heat, and they should be kept separate.

Now maybe corners have been cut and there are lessons to be learnt, but all this worlwide panic and condemnation of nuclear power is ridiculous.

Please give me viable green economically effective alternatives.

Wind power...cost per/MW generated to install windpower is not cost effective, in the UK the government pays subsidies to power firms to install and run them. Wave power is immature and again ineffective. Hydro is a viable alternative for the UK, but as soon as you start damming valleys people complain about drowning the rabbits. Nuclear does not automatically mean dangerous....

Hi!

It is true that the reactors will not result in a Hiroshima-like detonation; however, the destruction of Chernobyl and the depopulation of large parts of the Ukraine pretty clearly show that a nuclear reactor does not have to explode to cause catastrophic damage.

Pablo