Fukushima unit 2 liquification of uranium core. never seen before in history of nuclear power

ENEnews ^ | ENEnews

[yank in the UK]

Unit 2 we now know completely liquified. We’ve never seen this before in the history of nuclear power. A 100% liquification of a uranium core.

[rottndog]

Unit 2 we now know completely liquified. We’ve never seen this before in the history of nuclear power. A 100% liquification of a uranium core.

100% total BS....Same thing happened at Chernobyl...the core completely liquified and escaped the reactor vessel. It took them many months, but eventually the found the 'core'...it had oozed down beneath the vessel and combined with sand (which was surrounding the vessel) to form a highly radioactive glass. In the process, the uranium was diluted and lost it's critical mass--other than decay, it no longer had the capability of sustained fission reactions.

Same will happen (already happened) at Fukushima...all's that's left is for them to physically get inside the reactor plant and determine where exactly the molten core went. I'm willing to bet it's at the bottom of the vessel itself, where at this point it can't directly be observed.

The sky did not fall...

[rottndog]

Chernobyl's 'corium':


"Corium....it sounds like the name of an element that you never learned about in chemistry class. But its not an element at all; its a slang term in the nuclear industry for the "lava" that a reactor's core turns into after a meltdown."


Molten Uranium Fuel from Chernobyl called th "Elephant's Foot"

[justa-hairyape]

TMI even with just a partial core melt, still broke through a control rod solenoid seal at the bottom of the reactor. The corium flow was stopped inside the control rod mechanism tubing. Technically it had broke out through one of the RPV seals. The seals are just welds.

[NVDave]

When the question is asked in that form, I don’t know. Where are we talking? Core or somewhere on the RPV?

Core temps are estimated by looking at reaction by-products and, knowing how hot the situation has to be to create those by-products, we can say “the temperature in the core was at least X.”

eg, When the zirconium cladding on the fuel rods reached 1200C, it started a reaction where cooling water came apart into H and O, which resulted in the subsequent hydrogen explosions.

That said, the physics indicates that the overall maximum temperature in the core was probably reached in the first week after the tsunami, just as it was during TMI, with attending melting of the fuel rods into a lump on the bottom of the reactor, followed by a long decay period as the residual heat was removed.

[justa-hairyape]

Many Russians gave their lives to stop that corium flow. Would suggest we do not forget them. They probably wont forget us.

[justa-hairyape]

Got some time to get you some links now. Kept a small bookmark directory with the corium related links. From last year. Might be a good idea for me to reread some of this stuff anyway. My memory is not what it used to be.

Corium Behaviour and the Lower Head Thermal Response after a Core Meltdown

Excerpt from summary.

Thermal analysis showed that the RPV melt-through can be expected in one or two hours after the large core meltdown if no heat was removed from the outside vessel surface. Since corium is at high temperature, thermal radiation should also be modelled during the late in-vessel phase of a severe accident. The lower core support plate is the most exposed component to the radiative heat flux coming from the relocated material. In the case of the support plate failure, large portions of vessel internals would fall down into the lower head which would result in increased mechanical loading of the RPV wall and increased probability of the vessel failure.

More to follow.

[rottndog]

The corium flow stopped itself. Basic nuclear physics.

BTW, I do have a great deal of respect for the men who had to deal with that catastrophe. Same as I do for those dealing with Fukushima. Which is why I can’t stand people who try to sensationalize this event, and blow it far out of proportion.

[justa-hairyape]

The article below is also very enlightening. Worth a read if you are interested. Rupture failures are pretty much guaranteed for what happened at Fukushima.

BWR Reactor Vessel Bottom Head Failure Modes

[justa-hairyape]

You have respect for the Fukushima personal, but you deny recognition of actually how difficult the situation is over there for them. One negates the other.

[rottndog]

The situation over there is difficult, yes, but it is manageable....and they are handling it. They have the best minds in the world helping them as well. No need for panic and fear mongering.

[GOPJ]

Is this being reported by a Left-Wing Alarmist rag ?

Nope - they're still fretting about global warming...

[GOPJ]

Corium - how fine a dust? How hot? Half life? Thanks for the posts - interesting stuff...

[blueyon]

You do know that the link to CORIUM says there is nothing on it...........That was your point posting, correct? I am just trying to understand all of this

[Graewoulf]

” - - - When the question is asked in that form, I don’t know. Where are we talking? Core or somewhere on the RPV?”

I’ll try again: What is your estimate of the maximum temperature that COULD have been reached ANYWHERE at or near the general area of this site?

[Uri’el-2012]

;-)

[UCANSEE2]

And it melted its way to the center of the Earth, right?

No. It is not at the center. It is on it's way, and we don't know if it will ever get to the center, and even if it did due to atomic weight, it might take several thousand years. It's a long, long way from the crust to the center, and it's progress would be comparable to dropping a rubber ball into molasses.

[Chaguito]

I agree with both of you, about the site and Kaku. To read the comments on the ENENews site is to wallow in hysteria:

“My kids will never know the joy of going to their high school prom. They will never be able to work and save up for their first car, go on road trips and find new places to surf. Camp on the beach, walk in the rain and teach their own children the simple joys in life....I am so heart broken, this is not survivable people…end of story!”

[null and void]

However what would the movie be called if it were to be made in Japan?

Go-Geo...

[null and void]

But human beings are known to reproduce themselves, through a highly entertaining and interesting process about which I won’t go into details.

Where's the baby?

Oh, you have to wait nine months for that.

Hmmm. Then what was that hurry-up bit at the end?

[null and void]

Many Russians gave their lives to stop that corium flow. Would suggest we do not forget them. They probably wont forget us.

Yes. Every bit as impressive as the siege of Stalingrad.

These are not a people to be trifled with.