Earth quake in Japan!

[steamer]

Thanks for the updates Ken..keep them coming....I appreciate someone in the "know"....I also bookmarked the site you posted....

Man what a mess...

I wonder how many of the 50 operators that are still in there are going to make it out.....

Shades of Chernobyl......all over again.


Dave

 

[BillC]

Even looking at these these photos, it's hard to conceive.....


http://www.abc.net.au/news/events/japan-quake-2011/beforeafter.htm


BillC

 

[steamer]

1 minute, cars as far as you can see...the next...GONE....

speachless...

Dave

 

[Ken I]

Once again I take my hat off to those brave souls trying to contain the disaster at the Fukushima plant.

The situation is very fluid and one has no option but to read between the lines.

The Japanese are habitually reticent with bad news and problems, as a supplier of Japanese equipment I have to live with this continually.

The fire at #4 was in the spent fuel rods in the coolant pond and either was not suppressed the first time or has flared up again - almost certainly as a result of lowered liquid levels - hence the call for assistance to water bomb this target - since called off.
It is completely unclear as to whether this is chemical (Hydrogen) or nuclear - ie the spent fuel rods in the pond are delivering sufficient decay heat and possibly interacting with each other - there is a real risk of meltdown in the pond - this is a scenario that I don't think has been seriously considered before.

The "crack" in the roof of #4 seems curious - the roof's gone - so I am guessing this is a misinterpretation of a crack in the lid of the containment vessel (could of course be wrong) - but this seems to fit with the venting going on there.

The venting is of course laced with radioactive substances - such as Iodine and Caesium. Iodine lodges preferentially in the Tyroid gland - taking Iodine tablets saturates the gland thus preventiing uptake of the radioactive species. Iodine tablets do not "immunise" you to radiation.

So it now appears the #2 & #4 primary containment vessels are compromised and cannot be pressurised plus the venting is uncontrolled and poses the risk of further Hydrogen explosions.

A leak in the lid (#4) is less problematic than a leak in the torus (#2) which will inhibit or prevent covering the core with water.

Being unable to properly fill or pressurise these vessels vastly increaces the risk of further internal Hydrogen explosions which might damage the containment further.

When the 50 personell were pulled out because of a spike in radiation levels my first thought was they had given up and the situation was hopeless - but no they've gone back in - this probably means they felt confident enough to leave whatever systems they had running to continue unattended for a while - this is probably a good indicator.

Quite frankly I am amazed that this has gone on for so long without getting completely away from them and can only wonder at the bravery and committment of those tackling the problems.

Fortunately the weather has been playing along nicely blowing the bulk of the leakage out over the Pacific - most of it will settle into the sea - posing little risk to marine life - water is as good a radiation shield as Lead (not many people know that) - some increaced level of radiation is bound to be observed in fish etc. as some will undoubtedly find its way into the food chain - but I would expect this to be very little at the current leak rates.

Fears of radiation reaching Washington are perhaps simply alarmist - sure I think you can expect to see some increace but nothing of significance - although it will probably be reported as something like 10 times more than normal (10 times very little is still very little).

Ken

 

[Dan Rowe]

Once again I take my hat off to those brave souls trying to contain the disaster at the Fukushima plant.

water is as good a radiation shield as Lead (not many people know that) -

I agree that the guys facing this situation are true heroes.

The actual facts about the event will only be totally known after the fact when a through engineering analysis can be made and steps taken to reduce the risk in other plants.

Water is not nearly as effective at radiation shielding as lead.
http://en.wikipedia.org/wiki/Radiation_protection

Water is cheep and readily available so it is used for that reason.

Dan

 

[Ken I]

Dan,
Thanks for that reference and shielding table - salutory lesson in the use of "throwaway" remarks.

It depends on the radiation - energetic neutrons for instance pass through lead "easier" than water.

Water makes an excellect shield / moderator for a reactor where the primary radiation is neutrons but much less so for other forms of radiation.

My point was that radioactive materials dropping into the sea (whilst of grave concern) are environmentally a much lower concern than on dry land.

As always - "it all depends....."

Ken

 

[Mainer]

Incredible close-up video from Japanese TV of the tsunami coming through a town. The water just keeps getting deeper.

[ame]http://www.facebook.com/video/video.php?v=1605260179420&comments[/ame]

 

[Ken I]

The fire in the #4 cooling pond now seems beyond salvation. It was clearly containing at least the most recently removed spent fuel rods and probably much more.
Attempts to drop water by helicopter were called off on account of it being too radiologically hot for the helicopters - this also precludes any chance of going in on the ground - using a police water cannon ? - you may as well spit at it.

I am now begining to supect the explosions at 1,3 4 were pond related issues. The explosions that blew off the outer upper casement were unlikely to have come from deliberate or pressure venting which would have been discharged outside (although it might have overwhelmed the "filters" and discharged inside the building).

All four reactors are now unpressurised and at least two have the cores partially exposed and the status of the others is not really known.

Even units #5 & #6 are described as having "cooling problems".

This is getting indescribably bad, this is way worse than Three Mile Island and has the potential to even surpass Chernobyl.

There is a very real risk of this dominoing from 4 to 1 and the whole lot going.

I suspect they are very close to having to pull out and simply let it "burn".

Hope the weather holds.

"I would like to leave you on a positive note - but I can't - could you use two negatives" - Woody Allen

 

[Lakc]

The fire in the #4 cooling pond now seems beyond salvation. It was clearly containing at least the most recently removed spent fuel rods and probably much more.

I was trying to follow this closer today. What happens to all this material left uncovered? Does it simply increase in heat due to its mutual proximity until it becomes a molten mass? Brief criticality?

 

[Ken I]

Lakc,
The spent fuel rods still contain a lot of active Uranium but a significant amount of nasty fission products as well which act as Neutron inhibitors - as the pile gets older the control rods have to be withdrawn further and further - at some point you replace - which is what just happened at #4.

These rods are still capable of reacting and melting down so yes it can turn into a molten blob - that might burn through the bottom of the pond and become an unwelcome visitor to the outer containment vessel.
http://en.wikibooks.org/wiki/Radioactive_Waste_Management/Spent_Nuclear_Fuel

The problem is the amount of potential energy in these things - only about 30% of the Uranium is used in about 18 months - so theoretically there is enough energy there equivalent to 3 years output of 738MW (an overly simplistic calculation to be sure - but its not just going to cool down and stop like a blob of hot metal in water - and that's presuming there is only one set of spent fuel rods in the storeage - there may well be more).

As I mentioned in an earlier post the old British Windscale reactor has been cooled by seawater since 1957 (I think) and its now only approaching a condition where it can be dismantled.

Chernobyl still has a red hot core 25 years on.

If this "stuff" melts there is no way to deal with it other to entomb it and keep it cool.

If the reactor core melts it will eventually dribble into the "core catcher" void benath which can be filled with boric acid - if it comes through as a dribble (not a slug) then is it hoped this will cool it enough and hopefully sepparate it enough to stop the reaction.

Its starting to sound more Wiley Coyote the more I think about it - but WTH.

Hope it doesn't come to that.

Ken

 

[ksouers]

All four reactors are now unpressurised and at least two have the cores partially exposed and the status of the others is not really known.

Even units #5 & #6 are described as having "cooling problems".

This is getting indescribably bad, this is way worse than Three Mile Island and has the potential to even surpass Chernobyl.

Ken, I'm afraid that after all the data are analyzed they'll find that is has already surpassed Chernobyl.

It sounds as if they've already had at least one excursion. I'm certainly no expert on the subject, but I suspect the only way to get things under control is to disassemble the cores, or they disassemble themselves.

 

[Ken I]

Ksouers,
You may well be right !

I don't think dismantling is even a remote possibility even by an army of kamikazee technicians. (No slur intended but its a suicide mission.)

I don't know of anyone anywhere trying to take the lid off a "hot" reactor. On top of that the overhead crane has been destroyed in three of the 4 reactors.

They are pretty much out of options other than pumping in truely massive volumes of seawater - literaly filling the entire "box" with water and even that might not do it.

I'll be seriously impressed if they get a lid on this but that gets less likely with each passing minute.

Ken

 

[steamer]

I don't think dismantling is even a remote possibility even by an army of kamikazee technicians. (No slur intended but its a suicide mission.)


It was described thus.

""I don't know any other way to say it, but this is like suicide fighters in a war," said Keiichi Nakagawa, associate professor of the Department of Radiology at the University of Tokyo Hospital. "

Here is the source.

http://news.yahoo.com/s/ap/20110316/ap_on_bi_ge/as_japan_earthquake


Many workers died at Chernoybl after the explosion, putting up the containment building......

Russian or Japanese....they're still brave...thats for damn sure.....what an horrible way to die.

As an engineer, this whole event just breaks my heart. I haven't felt this bad since the Challenger disaster.

I was taking my udergrad physics when Chernobyl went up. My prof was a scientist at Los Alamos during the 50's. He had a grad student who was a Russion Nuke Engineer. I remember the lecture this guy gave about the most likely ( at the time) cause and what was going on. Suicide work on the containment was mentioned as, in all probability, a requirement.

Dave

 

[Lakc]

Thinking outside the box here, but bomb the reactor and waste pool? Would explosive disassembly be the lesser evil?

 

[steamer]

Thinking outside the box here, but bomb the reactor? Would explosive disassembly be the lesser evil?

I would say very uncontrolled at best...most likely just flinging it around.....

Dave

 

[Lakc]

I would say very uncontrolled at best...most likely just flinging it around.....

Dave

Yes, but isnt the danger its proximity to itself?

I see the BBC quotes someone in JNRC mentioning re-criticality, surely that gamma release would be worse?

 

[steamer]

ahhh see your point..

Maybe...but I lack the expertize here to make a call...but the "hair on the back" meter is pegged at the "don't do it " mark.

Besides think of the radioactive mess....not that its real good right now! :-[

this does truly (&#$&*^@ !

 

[Ken I]

I've had the same thought myself but simply not knowledgeable enough to make that call.
The SL-1 blew so violently it stopped the reaction - so the idea is not as nuts as it sounds - but I would guess the size of this thing precludes this idea - and besides can you see any politician giving the green light ?

Dave, I don't know why but like you I feel a personal sense of tragedy as an engineer.

Those spent fuel rods are leathally radioactive - quoting from the Wiki source I listed earlier - a spent fuel rod after 10 years in storage will emit 20000 Rems per hour at 1m - an exposure of 5000 Rems (15 mins) gaurentees immediate incapacitation and death within a week.

We have a pond full of these things on fire and potentially going into meltdown.

The are over 160000 of these things in storage in the US.

The risks of this stuff has been known for years but we have failed do anything about it.

One thing is for sure the analysis of future atomic energy is going to require addressing this issue.

We have solutions - turn the waste into metal oxide glass encased within another glass outer - like a hockey puck - waste Plutonium for reprocessing is often processed this way for transport (those heavy "flasks").

We can drop these in a geologically active subduction zone - say the Marianas trench - where it will be slowly ground back into the earth's mantle over millions of years.
Its too deep to be got at by terrorists and would be so difficult to recover and process you might as well start from scratch.

From an engineering point of view this makes perfect sense - but you can clearly imagine the ecological opposition.

Ken

 

[steamer]

The Japanese officials are talking about burying it now.

Dave

 

[Ken I]

Dave,
They really don't have any other option. The SL1 reactor was buried with 60' of earth on top of it - and a tombstone what's more.

It looks like they are going to be able to restart the main pumps today (or at least one of them) this should bring the situation under control.

I'm guessing the plant is a complete write off and will have to be "buried". The clean up is going to take years - that's assuming clean up is possible - since the plant has not gone into complete meltdown that would appear likely.

Its certainly going to pose some challenging engineering problems.

Prognosis at this stage is several times worse than TMI but still nothing like Chernobyl.