BBC: Tepco halts Fukushima cooling plan

[GliderGuider]

Tepco halts Fukushima cooling plan

Japanese engineers have abandoned their latest attempt to stabilise a stricken reactor at the Fukushima nuclear plant.

The plant's operator, Tepco, had intended to cool reactor 1 by filling the containment chamber with water. But Tepco said melting fuel rods had created a hole in the chamber, allowing 3,000 tonnes of contaminated water to leak into the basement of the reactor building.

The government and Tepco (Tokyo Electric Power Company) said it would take until next January to achieve a cold shut-down at the plant. Government spokesman Goshi Hosono said the latest setback would not affect the deadline.

Tepco says it will come up with a new plan to stabilise the reactor by Tuesday.

The PR dance continues.

[Warren Stupidity]

1. I'm not a nuclear physicist but

if the fuel rods have melted their way through the chamber, aren't they right now melting their way through the basement, and won't they continue to melt their way down until they have melted themselves out of existence?

[TalkingDog]

2. SHHHHH!!! Stop making sense. It upsets the apple cart.

nt

[FBaggins]

3. No. "Melted" (past tense) does not mean "currently liquid"

The primary containment is designed to "contain" a meltdown. There has been much speculation re: whether or not it would suffer at that, but no... Some/all of the core melting and falling to the floor containment does not imply that it will continue to burn through every remaining barrier. Particularly if there was water at the bottom of that containment.

Had it done so, you would expect much higher radiation readings.

Indications are that the core (or part of the core) settled to the bottom of the containment and resolidified. Cooling water is leaking out (and thus radioactive materials), but not a portion of the core.

[Warren Stupidity]

4. "The plant's operator, Tepco, had intended to cool reactor"

Again - I'm no expert, but that statement indicates that the rods are not being cooled, consequently they are still melting.

[caraher]

5. That doesn't immediately follow

Something can only be melting if its temperature rises above its melting point. That may or may not be the case right now.

You may be right, but lack of water cooling does not in itself imply a particular temperature.

That said, this is certainly a bad development.

[jpak]

6. Your speculation is worthless

yup

[FBaggins]

7. There wasn't speculation there so much as a response to speculation.

You really think that it makes sense to say that if they melted through one layer... there's nothing to stop them until they don't exist any more?

[Fledermaus]

8. You've been 100% wrong so far.

where's the corium now?....You don't know jack!

[FBaggins]

9. And yet you can't give any examples?

Why is it you run every time you're challenged on that BS?

One would think that you would be happy to provide a long list of those errors just for entertainment. I know I get a kick pointing out yours.

Let's play a game. I'll give you one of your knee slappers and you follow with one of mine. I'll start.

You claimed that the containment design at fukushima was the same as that at chernobyl. Thank god you were wrong, eh?

Your turn. Don't worry. I won't hold my breath.

[SpoonFed]

11. You mean like your statements to the effect that Fukushima isn't worse

Than TMI, the readings at he plant pose no human health threat even to workers, crap like that?
INES 7 and 2Sv readings at the door make you look like a fool, but pls conitnue for our amusement

Oh right INES is stoopid cause this can still get worse (your 180 from weeks of this can't get worse). And 2Sv is only bad if you stay there, kinda like the centre of the sun...

And my personal recent favorite, Pu isn't harmful cause there already is lots from 1945...?!?!?!!!
Your hobbit hole has a CO leak

[FBaggins]

12. Nope... I mean actual examples of errors. Not ones you invent.

statements to the effect that Fukushima isn't worse Than TMI

You mean like:

"it's more significant than TMI"...""this is a more serious challenge than TMI"

"Yes, it's very clearly worse than TMI"

"TMI was a five and I don't think that this event is LESS significant than TMI at this point"

All in the first few days after the incident.


the readings at he plant pose no human health threat even to workers,

You mean readings that didn't pose a threat? Why would that be wrong?

Once again... how about backing it up rather than just making the claim?

Oh right INES is stoopid cause this can still get worse

We can only judge by what had happened to far. "Could get worse" isn't particularly relevant. Especially since I regularly prefaced my comments by saying "assuming it doesn't get worse".

And my personal recent favorite, Pu isn't harmful

Sorry... you only get points for actual errors in my statements... not statements you wish to put into my mouth for your own convenience. I never once said that plutonium isn't harmful. In fact I said just the opposite.


On edit - Whoops. I didn't realize it was you SF. Haven't given you your first error to play with.

It's been well over a month since you said that those three guys who exposed their feet had a 50/50 chance of death within 30 days. That I was wrong to point out that the reporting mistakenly cited dose levels rather than activity/exposure.

How are they doing?

[wtmusic]

17. The more benign materials that they melt through

the more their purity is diluted and the cooler they get. Workers are trying to speed that process by adding boron.

At some point they will become a (relatively cool) sludge which will not be hot enough to crack concrete.

The challenge will be to contain that still highly-radioactive sludge.

[SpoonFed]

10. How exactly did they "halt" the plan,

Like did they ball up the filthy chunk of toilet paper they hastily scribbled it on, or was it that they threw the back of the envelope scrap into the fireplace?

[madokie]

13. It appears that they have no

fucking idea as to what to do next. Just what we need is a run away nuke plant on this planet. Six nukes at this one compound so I wonder what the chances of this spreading to the others.

shit or go blind and neither is very encouraging.

[nadinbrzezinski]

14. You mean we now have a CORE VESSEL BREACH?

REALLY? Why not USE ACTUAL LANGUAGE BOYS?

[Throckmorton]

15. The terms I learned in my mis-spent youth were,

Reactor Pressure Vessel, holds the core and reactor coolant.

Primary Containment, contains the Drywell and Torus, and is inside the isolation boundary.

Secondary Containment, the building that surrounds everything, and contains the Spent Fuel pool.


So TEPCO, where are the melted fuel fragments?

Are they all still in the Reactor Pressure vessel?

Are some of them outside the reactor pressure vessel but still inside the Primary Containment?

Are some of them outside the Primary Containment, but still inside the Secondary Containment?

Are some of them now outside the Secondary Containment?

I don't know if it is still translation problems, the media not understanding TEPCO’s answers, deliberate obfuscation, or just me being thick as a rock, but it seems like they never use the same descriptions twice.

[nadinbrzezinski]

16. at this point I think it is our media helping theirs

keep face...

:-)

And they cannot and will not tell us how bad it is. You see, with Chernobyl they were HAPPY to give you all the gory details... commie state yada, yada, yada...

Both TMI AND this have lousy coverage... there IS an industry to protect.

[kristopher]

18. The graphic might be here...

http://www3.nhk.or.jp/nhkworld/index.html

I have a slow internet connection so I will leave it to you to browse the videos, but here is what I saw on the NHK satellite news reports:

NHK news has been showing the mass as being located at the bottom of the RPV with accompanying reporting that the RPV has "holes in it" as a result and that the "containment vessel" (shown in graphic as the Primary Contaiment system) "is probably leaking as well".

That was on the 13th; by the 15th graphic showed the corium in the same place at the bottom of the RPV bt with added animation depicting water being pumped into the top of the PRV and pthen running out of the bottom of the RPV under the mass.
"the nuclear fuel has started melting and damaging the reactor walls, it is thought that the containment vessel is also damaged and that radioactive water has started seeping into the basement".

They increased the amount of water being pumped into the reactor from 8 to 10 tons per hour.


Today they described it this way, "the meltdown is thought to have created a hole in the #1 reactor and damaged its containment vesel. Huge amounts of highly radioactive water are likely to be leaking inside the reactor building".
They say #2 & #3 "may have also have undergone meltdowns" effectively sending them back to square one in planning if true.