Edit:22 Update 2: Experts warned Fukushima of tsunami threat 2 years ago.

[NikolaeVarius]

So what these reactors don't have a dormant state and can't be turned off at all and require constant cooling? What happened to control rods, or removing the fuel and storing it as you would when delivering new fuel, etc?

They turned it off. This is residual heat that is building up because it's not being actively cooled.

 

[iGas]

It is.

That maybe the case, but this incident is going to be an achilles heel for the nuclear industry.

 

[Locut0s]

That maybe the case, but this incident is going to be an achilles heel for the nuclear industry.

Sadly yes.

 

[Brovane]

They turned it off. This is residual heat that is building up because it's not being actively cooled.

That is correct. As soon as the earthquake happened the seismic sensors at the reactors inserted the control rods fully into the reactor to basically shutdown the reactors. However there is enough residual heat that it can take several weeks before the reactor is cooled down enough that active cooling is not required.

My understanding is that the Tsunami wave took out the backup Diesel generators. With the plants offline and the electrical grids offline the reactors depend on emergency diesel generators for onsite power for pumps etc. However those generators where taken out by the wall of water. So the ability to run the cooling pumps where taken out. There was a battery backup but that has only lasted so long. So they have been struggling with this issue. So far it appears that the containment dome's are holding. This was the key thing that Chernobyl didn't have which was a containment dome. These Japanese reactors and 3-mile island all have containment domes to hopefully contain the core and radiation in case of a meltdown. This protection worked with 3-mile island. We will have to see if it works here.

 

[Jeff7]

Yeah it has nothing to do with them having had an 8.9 EARTHQUAKE!

Seriosuly their disaster recovery plans are second to none in the world. But they are dealing with something that no plan can really deal with easily.

And a tsunami. And numerous 6+ aftershocks, with at least one that was 7+.

 

[exdeath]

I see, the existing heat doesn't just disappear instantly as soon as the rods are seperated... DUH :awe:

 

[techs]

That is correct. As soon as the earthquake happened the seismic sensors at the reactors inserted the control rods fully into the reactor to basically shutdown the reactors. However there is enough residual heat that it can take several weeks before the reactor is cooled down enough that active cooling is not required.

My understanding is that the Tsunami wave took out the backup Diesel generators. With the plants offline and the electrical grids offline the reactors depend on emergency diesel generators for onsite power for pumps etc. However those generators where taken out by the wall of water. So the ability to run the cooling pumps where taken out. There was a battery backup but that has only lasted so long. So they have been struggling with this issue. So far it appears that the containment dome's are holding. This was the key thing that Chernobyl didn't have which was a containment dome. These Japanese reactors and 3-mile island all have containment domes to hopefully contain the core and radiation in case of a meltdown. This protection worked with 3-mile island. We will have to see if it works here.

However, iirc, once the actual core starts to melt the reaction resumes. The moderator(the control rods) and the fuel mix unevenly so there are some areas where the moderator has little or no effect. Apparently the moderator needs to be at uniform positions within the core.



I could be wrong about this, but I remember reading it somehwere.

 

[Locut0s]

I see, the existing heat doesn't just disappear instantly as soon as the rods are seperated... DUH :awe:

They also continue to produce more heat for some time.

 

[alkemyst]

6th failed reactor....lol they are really fighting for the title of worlds worst disaster recovery plan.

You are either showing true ignorance or simply are anti-Japan.

Which is it?

 

[MikeMike]

Dear Japan: We all wish you the best, minus the nutjobs who no one cares about... This is such a severe blow to the future of U.S. nuclear plants that I really dont like it...

THE LEFT CAUSED IT TO FURTHER THEIR ANTI NUCLEAR STANCE!!! (JK)

 

[MikeMike]

Dear Japan: We all wish you the best, minus the nutjobs who no one cares about... This is such a severe blow to the future of U.S. nuclear plants that I really dont like it...

THE LEFT CAUSED IT TO FURTHER THEIR ANTI NUCLEAR STANCE!!! (JK)

 

[zerocool84]

They're fearmongering because it gets them page visits. What is more interesting "HOLY FUCK THERE IS A NUCLEAR REACTOR THAT'S ABOUT TO CRITICAL! WE DIDN'T LISTEN! WE DIDN'T LIISSTEEENNNN" or " There is possibility that a nuclear reactor may have undergone a partial meltdown, investigators still attempting to cool reactor core"

and now there is no way we're going to get any more nuclear reactors built here in America. We need them more than any other country in the world and it's still the best way to get energy but this Japan incident basically killed all hope of ever getting any more built.

 

[alkemyst]

yeah because are people are idiots in fear. the 30 round clip deal is big all over our country over one incident. It's making a ton of money for those involved.

 

[davmat787]

and now there is no way we're going to get any more nuclear reactors built here in America. We need them more than any other country in the world and it's still the best way to get energy but this Japan incident basically killed all hope of ever getting any more built.

Not so sure about this. Proponents could argue that it took a once in a century or two natural disaster to happen within hundreds of miles to the reactors. Also I don't think we would build them right near the coast either. Also depends on how this ends up, if after all of this fearmongering things don't turn out anywhere near as bad, maybe people will realize how safe it can be when coupled with the latest advances. I dunno tho, just tossing this out there.

 

[BoomerD]

So...if the reactors go into meltdown, and (worst case scenario) the radioactive plume reaches the USA, can we call it a terrorist attack and nuke them back? (again)

We NEED retribution for tentacle pron and that garbage "little girl music" that uhohs keeps posting.

If gawd doesn't get ya...we will.

 

[silverpig]

Now, I have no idea of the logistics of the plant or anything, but one might figure they'd have had enough time by now to airlift in some massive diesel generators and fuel by now right? I mean, even if Japan's infrastructure is messed up, surely South Korea has the ability to drop ship something like that and get it there in under 6 hours.

 

[the DRIZZLE]

Now, I have no idea of the logistics of the plant or anything, but one might figure they'd have had enough time by now to airlift in some massive diesel generators and fuel by now right? I mean, even if Japan's infrastructure is messed up, surely South Korea has the ability to drop ship something like that and get it there in under 6 hours.

Right but remember things have gotten worse since the original problem. Half of the reactor building of one of the units blew up. They may not have the ability to operate that unit normally anymore even if aux power was restored. You are also talking about massive generators. They could be 10% of the capacity of the nuclear plant which would be 500 MW. Thats a decent sized power plant by itself, not something you can just airlift in.

 

[The Boston Dangler]

However, iirc, once the actual core starts to melt the reaction resumes. The moderator(the control rods) and the fuel mix unevenly so there are some areas where the moderator has little or no effect. Apparently the moderator needs to be at uniform positions within the core.

I could be wrong about this, but I remember reading it somehwere.

yes, if the solid fuel melts its way out of the fuel rods and pools at the bottom, there is nothing to absorb neutrons and prevent runaway fission. that's why they are mixing in boron with the seawater they are pumping in.

the fuel used here is MOX , which is plutonium (very nasty) mixed with low grade uranium (still quite nasty). its purpose is to consume the plutonium from decommissioned weapons and the plutonium produced from some uranium-fueled reactors.

They also continue to produce more heat for some time.

5 billion years and counting

 

[techs]

and now there is no way we're going to get any more nuclear reactors built here in America. We need them more than any other country in the world and it's still the best way to get energy but this Japan incident basically killed all hope of ever getting any more built.

Actually we need nuke plants the LEAST of any country in the world.

We have enough coal to last hundreds of years for our electrical generation. Plus with the huge amount, staggering actually, of natural gas now recoverable with new hydrofracturing techniques we are swimming in fuel for electrical generating plants.

 

[The Boston Dangler]

Actually we need nuke plants the LEAST of any country in the world.

We have enough coal to last hundreds of years for our electrical generation. Plus with the huge amount, staggering actually, of natural gas now recoverable with new hydrofracturing techniques we are swimming in fuel for electrical generating plants.

there ain't no free lunch. burning coal releases exponentially more radiation that has ever been released by nuclear plants. then there's massive amounts of CO2 and the effects of hydrofracturing. then there's the possibility that coal and gas might have more value as feedstock for building materials and synthetic oil.

 

[rcpratt]

However, iirc, once the actual core starts to melt the reaction resumes. The moderator(the control rods) and the fuel mix unevenly so there are some areas where the moderator has little or no effect. Apparently the moderator needs to be at uniform positions within the core.



I could be wrong about this, but I remember reading it somehwere.

The control rods are neutron absorbers, not moderators. But yes, that is a concern.

 

[IceBergSLiM]

Yeah it has nothing to do with them having had an 8.9 EARTHQUAKE!

Seriosuly their disaster recovery plans are second to none in the world. But they are dealing with something that no plan can really deal with easily.

Their plans obviously sucked. Why wouldn't they be anticipating 8.9 quakes sitting on one of the largest fault lines in the world in the ring of fire.

If they didn't have a good plan they shouldn't have built hundreds of nuke plants. Seems like a logical conclusion to me.

 

[IceBergSLiM]

You are either showing true ignorance or simply are anti-Japan.

Which is it?

its pretty ignorant building hundreds of nuke reactors in one of the most prone to massive earthquakes locations in the world while having clearly insufficient disaster recovery plans. THAT IS IGNORANT>

 

[IceBergSLiM]

Really?

yes

 

[Ichinisan]

its pretty ignorant building hundreds of nuke reactors in one of the most prone to massive earthquakes locations in the world while having clearly insufficient disaster recovery plans. THAT IS IGNORANT>

You somehow think planning can completely negate even the most epic disasters? Hello, Captain Hindsight!