News Japan Earthquake, Tsunami, & Nuclear Disaster

[Urwumpe]

Radiation traces were found in Scotland and Holland form japan......

Traces had also already been detected by German stations. That is nothing extremely special, we even detected traces here of the failed nuclear test underground by North Korea. Since most radioactive isotopes are pretty rare in nature, they simply stand out in dust samples.

 

[Belisarius]

Funny clip from Fox News where the blond bombshell (a dud) Megyn Kelly tries to stir up a bit of panic about it in the US

http://www.mediaite.com/tv/japanese...s-water-megyn-kelly-asks-if-we-need-to-worry/

 

[statisticsnerd]

http://e.nikkei.com/e/fr/tnks/Nni20110330D30JF414.htm

Media reports said that the government and the experts have been studying the feasibility of new steps such as covering reactors of the plant with special cloth to reduce the amount of radioactive particles flying away from the facility and using a big tanker to collect the contaminated water.

From the failed Extension Cord of Glory to The Magic Rag !

 

[jedidia]

what's actually hindering them of just walling the reactors in to prevent further fallout a la chernobyl? I thought maybe the radiation is too dangerous, but seeing that they still have limitted access to the control room suggests that such a measure would be possible. They can't possibly hope to get these reactors working again anyways.

 

[Notebook]

http://www.bbc.co.uk/news/world-asia-pacific-12903725

Japan to scrap stricken nuclear reactors

N.

 

[SiberianTiger]

what's actually hindering them of just walling the reactors in to prevent further fallout a la chernobyl? I thought maybe the radiation is too dangerous, but seeing that they still have limitted access to the control room suggests that such a measure would be possible. They can't possibly hope to get these reactors working again anyways.

I believe encasing in a sarcophagus is more difficult here in Fukushima than it was in Chernobyl, because the volume to be encased is much bigger (at least three reactors together with the spent fuel pools, instead of just one blown up power unit. Also, they must build it in earthquake-resistant manner. I'm mind picturing a huge artificial mountain heaping over the place when I think of it. :shrug:

And in addition, they might not still have lost a hope for restoring some of the capacity back, who knows.

 

[Belisarius]

I'm mind picturing a huge artificial mountain heaping over the place when I think of it... they might not still have lost a hope for restoring some of the capacity back, who knows.

What would a radiation containment "sarcophagus" really be like in this case? I am imagining a huge mound of sand topped off with thick plastic sheeting. Then a sea containment barrier in some form. Big plastic sheeting to contain water flows from the coast near Fukushima?

As for trying to reactivate the facility, that is surely out of the question. I'm just hearing now on Al-Jazeera that the Japanese govt has announced that it will be "scrapped". It's a write-off.

---------- Post added at 10:46 AM ---------- Previous post was at 10:28 AM ----------

UPDATE:

That's official, the reactors 1-4 plus spent rod pool are being decommissioned:

http://www.bbc.co.uk/news/world-asia-pacific-12903725

Notice the reference to the TEPCO boss (president or CEO, depending on source):

Tepco's president Masataka Shimizu has been admitted to hospital, suffering from high blood pressure and dizziness.

Should we send him a bunch of flowers?

 

[Urwumpe]

Every reactor would need its own sarcophagus, which is one of the problems. Next, you have everything that makes this job hard, Earthquakes, Tsunami risk and a large number of people around the place.

I think, a Sarcophagus would be the wrong solution here, a temporary one might be needed, but the better goal would be disassembly of the reactors, decontamination of the soil, and disposal of everything contaminated. This means many ten thousand tons of nuclear waste and serious effort, but a sarcophagus that needs a complete overhaul every 10 years would be less wise. The damaged reactor needs to be removed from this high risk place.

---------- Post added at 10:59 AM ---------- Previous post was at 10:58 AM ----------

Should we send him a bunch of flowers?

Compared to what his workers and day-laborers have to suffer because of his lack of resolve, he can be happy about the flowers.

 

[Cairan]

One thing which is complicating matters is the fact that Japan uses two frequencies for it's electrical grid. So they can't spread the load between eastern Japan, which includes Tokyo) and western Japan. Sounds rather silly, considering that with all the destruction caused by WWII they could have scrapped either the 50 or 60 Hz grid in favor of the other...

---------- Post added at 11:48 AM ---------- Previous post was at 11:41 AM ----------

As far as the sarcophagus goes... wouldn't it be simpler just to encase the reactor vessels and let it sink in the nearby Japan trench? I know everyone is not too warm towards disposing of nuclear waste in the ocean, but in this case I'd make an exception...

1) the very cool, unlimited and high pressure cool water supply at the bottom of the trench would quench the cores
2) being at the bottom of the trench, the stratification of deep waters and the bathymetry would prevent exchanges with the surface or abyssal waters
3) the isotopes which are most worrying as far as radiation goes are all in solid form and rather dense except for iodine, but as stated, it's half-life is so short and the bottom currents so slow that it wouldn't spread very far from the sunken cores.

 

[Sky Captain]

I don't think breaking out reactor vessels from all that building wreckage would be feasible. Those reactors are made from thick steel, they are very heavy, when filled with water and remains of the core probably over 1000 tons. Only ship based cranes can lift such loads and the reactors are sited ~200 m from shore. Getting a crane ship nearby would recquire extensive dredging which would stirr up radioactive mud.

 

[Urwumpe]

I don't think breaking out reactor vessels from all that building wreckage would be feasible. Those reactors are made from thick steel, they are very heavy, when filled with water and remains of the core probably over 1000 tons. Only ship based cranes can lift such loads and the reactors are sited ~200 m from shore. Getting a crane ship nearby would recquire extensive dredging which would stirr up radioactive mud.

They managed to do the very same in Germany already a few hundred kilometer away from the sea.

What goes into the building, also goes out of it.

 

[Wishbone]

What about building 4 pyramids to entomb the reactors? The world is dealing with two separate problems: how to contain the cores and other devilishly radioactive stuff NOW, and how to prevent long-term contamination in the years to come.

EDIT: To clarify (and justify) the seemingly wasteful two-step approach: taking out the cores and RPVs now is going to cost much more than two or three years out, because of decay.

 

[Cairan]

I think we have a major issue here: http://www.guardian.co.uk/world/2011/mar/29/japan-lost-race-save-nuclear-reactor

Still trying to find other sources than Guardian... will update the post as I find other references.

 

[Urwumpe]

What about building 4 pyramids to entomb the reactors? The world is dealing with two separate problems: how to contain the cores and other devilishly radioactive stuff NOW, and how to prevent long-term contamination in the years to come.

The problem is: How do you build a pyramid also BELOW the cores - the pyramid principle only protects the air, but not the soil and the water.

It is actionism, not more - if you have tons of contaminated water you also need to keep that in check.

 

[Wishbone]

I suppose that's why my Ph.D. was not in Civil Engineering

What is your take on the sequence of steps, assuming at least one of the cores has seeped onto the concrete?

EDIT: The IAEA site is silently going into the realm of dark humour:

Based on measurements of I-131 and Cs-137 in soil, sampled from 18 to 26 March in 9 municipalities at distances of 25 to 58 km from the Fukushima Nuclear Power Plant, the total deposition of iodine-131 and cesium-137 has been calculated. The results indicate a pronounced spatial variability of the total deposition of iodine-131 and cesium-137. The average total deposition determined at these locations for iodine-131 range from 0.2 to 25 Megabecquerel per square metre and for cesium-137 from 0.02-3.7 Megabecquerel per square metre. The highest values were found in a relatively small area in the Northwest from the Fukushima Nuclear Power Plant. First assessment indicates that one of the IAEA operational criteria for evacuation is exceeded in Iitate village. We advised the counterpart to carefully assess the situation. They indicated that they are already assessing.

 

[Urwumpe]

What is your take on the sequence of steps, assuming at least one of the cores has seeped onto the concrete?

I'll remember the T-Shirt of the bomb disarmament team: If you see me running, run faster.

Seriously speaking: Now you need robots or suicide candidates. You need to move workers (alive or not) not only towards the most dangerous parts of the power plant, but also as close to the nuclear mass as possible.

You would have to do three steps of actions:

1. Immediate containment. Essentially you do every thinkable action to ensure that the containment building is closed. You fix any gap by the explosions, if needed use brute force to close pipe connections if the valves fail. You still need the containment for cooling the nuclear mass, so you can't instantly destroy it.
2. Next, you cool the repaired containment structure from outside, filling the inside with sand by pumping a mix of sand and water. Such a mix reaches every corner of it and does not produce salt layers that insulate. No circulation from inside the containment to outside. This will carry lots of nasty gases with it and make your work harder. Everything you vent from inside during the process has to be captured and disposed. It is no longer just the short lived gases that a normal reactor produces.
3. After cooling down to hand warm temperatures, you start with disassembling the reactor. Layer by layer, from top to bottom. All under sealed atmosphere, like you always need for NBC threats. You work slowly and let robots do most of the work, measuring temperature and composition of the layer that you remove for checking the state of the reactor below. This is where a temporary sarcophagus makes sense. But this has to extend below the reactor, which would mean you essentially dig the reactor out of the soil.

Containment, Cooling and safe disposal at once are the only real methods I see here - just one of each wouldn't help. Cooling can't work because you leak water and spill more waste into the environment. Cooling and Containment without disposal will result in you having to build new layers of protection above and below the reactor core.

Disposal would also mean the top 15 meter layers of the soil in a very large region, if the geology is not your friend. The ground water layer is likely affected there and slowly spreads the waste below the feet of the workers.

 

[RGClark]

Solutions to the Japanese nuclear crisis?

It is unlikely that the four nuclear reactors under duress at
Fukushima will ever be used again. There have been some suggestions
that all four reactors be entombed under a sarcophagus as was done
with Chernobyl. This however is not an ideal solution. In such a
scenario there is the constant fear that the nuclear material will
come in contact with the water table as time goes on leading to
widespread contamination of drinking water. This is already a concern
with the discovery of leaks of contaminated water out of the
reactors at Fukushima.
Another danger is large steam explosions with a meltdown if the hot
fuel melting through floors of the plant reaches a large source of
water such as ground water under the plant. This could lead to large
explosions leading to large scale radioactivity release. This was a
worry for years later with Chernobyl even with the sarcophagus
covering the reactor.
On the other hand there is a worry that the crisis could go on for
months or even years:

More radioactive water spills at Japan nuke plant.
By SHINO YUASA, Associated Press =96 Mon Mar 28, 5:49 pm ET
http://news.yahoo.com/s/ap/20110328/ap_on_bi_ge/as_japan_earthquake

I therefore suggest means be explored for removing the radioactive
material from the area over a short time frame. One possibility: move
the entire buildings. Truly large buildings have been moved in the
past up to 15,000 tons:

The Five Heaviest Buildings Ever Moved.
by Molly Edmonds
http://science.howstuffworks.com/engineering/structural/heaviest-building-moved5.htm

The heaviest parts of the Fukushima buildings that would have to be
moved would be the concrete and steel containment vessels. This
article on p. 6 estimates their mass as about 2,500 tons:

Nuclear Accident in Japan.
http://www.asiaa.sinica.edu.tw/news/_upload/201103JapanNuclearAccident.pdf

On the other hand this article gives the containment vessel weight
of a more modern nuclear reactor type as 910 tons:

Construction progresses at Shimane 3.
27 July 2009
http://www.world-nuclear-news.org/NN-Construction_progresses_at_Shimane_3-2707094.html

The GE Mark I reactors used at Fukushima are known for their
leightweight containment vessels so they actually might weigh less
than the Shimane 3 containment vessel.
Japan is a small island country so there would really be no where
safe to put these damaged reactors. Then it might be necessary to move
them by sea on barges to some large deserted region.
Another problem is that large electricity generation buildings block
the path to the pier. These could be razed, an expensive and time
consuming prospect, or you might have to first move the reactor
buildings sideways, leveling much smaller buildings on the side, then
move the reactor buildings towards the pier.
In the article on the moving of the large buildings its surprising
how low the cost is. For instance the second biggest move was at about
7,400 tons and cost only $6 million. However, a consideration is that
for these moves the engineers had to add extra supports inside the
buildings to ensure they would remain intact during the lifting and
the transportation. This would be a problem if this was necessary for
the reactor buildings if this was required inside the highly
irradiated areas.


Bob Clark

 

[Belisarius]

Any of these methods involves a tremendous expense and huge risk to the workers involved, and all of them involve years of work.

My mind is boggling already at the idea of disassembling these reactors or moving them whole by ship, and using armies of rad-hardened robots or suicide workers to do the work. All at risk of further earthquakes at any moment to disrupt the effort.

Not even Chernobyl was as problematic as this threatens to be.

So is this officially the worst civil nuclear catastrophe in history?

 

[Urwumpe]

So is this officially the worst civil nuclear catastrophe in history?

Wait until we have passed the apogee. :lol:

Currently we just know, that things are almost as bad as Chernobyl, and the things worse than Chernobyl are likely.

But we don't know much - we can't even tell if the Plutonium is from inside the reactor or not, because TEPCO doesn't give the information of the isotope ratios out. Which is pretty important, if you are close to North Korea.

Its too soon to start with superlatives. It is at least already far beyond the design basis accident that is often used as reference for nuclear safety. But how far beyond and if it is really worse than Chernobyl... that is the problem for experts and historians.

Even in the densely populated Nippon, nobody was as arrogant to the physics as the Soviet planners, who build the worker settlements for the nuclear power plants right at the fence.

Just as example how poor the situation is for telling about the reactor state:

The strong nuclear contamination is the only solid evidence for a containment breach and partial meltdown. (Solid as in: Independent sources can confirm this data, not just TEPCO; not solid as in: Is direct evidence of a meltdown)

The data that TEPCO published is for example 85°C at the bottom of the RPV of Unit 2 - sure no meltdown there, Unit 1 has 177°C at the bottom and 380°C at the ECCS water spray nozzles.

 

[jedidia]

wouldn't it be simpler just to encase the reactor vessels and let it sink in the nearby Japan trench?

And in fifty+ years we have Godzilla rising out of the Trench? :blink: