News Japan Earthquake, Tsunami, & Nuclear Disaster

Latest news: The cooling pumps currently operate on battery power and will stop functioning in a few hours unless electricity is restored.

Still, there are many options to prevent a nuclear disaster (in this case, destruction of the fuel elements by residual heating), the question is just, are these options available right now. Also not known is the state of the nuclear power plant itself, it is possible that more parts are damaged by the unthinkable forces as known.

There are no news yet, that any nuclear reactor failed the emergency shutdown, which would be easily possible for BWRs, since they need to insert their control rods from below by powerful hydraulic actuators.

During an earthquake, it is not impossible that the control rod channels become deformed and control rods stuck. In this case, only the forming of steam voids would reduce nuclear reactions - there would be no violent power transient like it happened in Chernobyl, but you can still expect pressure vessel failure as worst case (eg, by meltdown).
 
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Forecast map of the tsunami :


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http://www.bbc.co.uk/news/world-asia-pacific-12715415

A Japanese ferry with 100 people on board was sunk by a 10 meters-high wave. There was nothing to do.
 
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A Japanese ferry with 100 people on board was sunk by a 10 meters-high wave. There was nothing to do.
That's just horrible.. of course the whole disaster is horible, but they really didn't had any chance :(
 
http://timesofindia.indiatimes.com/...shes-away-homes-Kyodo/articleshow/7681832.cms

TOKYO: A dam in Japan's northeast Fukushima prefecture broke and homes were washed away, Kyodo news reported on Saturday, after the biggest earthquake in the nation's history wreaked death and havoc.

The 8.9-magnitude quake - the seventh biggest ever recorded - generated a monster wall of water that pulverised the northeastern city of Sendai, where police reportedly said that 200-300 bodies had been found on the coast.

At least 310 people were killed in the massive earthquake and following tsunamis, police and press reports said.

:oh:
 
That's just horrible.. of course the whole disaster is horible, but they really didn't had any chance :(

Today many thousand people likely didn't have any chance. There is a complete train missing as well.

Also, freak waves or tsunamis and a ferry in shallow water are a bad combination, that reminds me on an earlier accident during a storm.

[ame="http://en.wikipedia.org/wiki/Toya_Maru"]Tōya Maru - Wikipedia, the free encyclopedia[/ame]

---------- Post added at 05:43 PM ---------- Previous post was at 05:43 PM ----------


Ouch!
 
More than 1000 people killed now...
 
Been following this all day. I would be quite surprised if the final death toll isn't in the high thousands - maybe in to five figures. Those poor people on the coast wouldn't have stood much of a chance, with only minutes in between the earthquake and the tsunami hitting the mainland. With some of those images that we've seen today, I think we know for sure that the "hundreds" being reported as dead so far will rise significantly.

A devastating reminder that we live on an active planet. :(
 
Here at work we are getting updates like this one...

Update from Nuclear Energy Institute -
Quake Triggers Precautionary Evacuation
of Residents Near Fukushima-1 Nuclear Power Plant
After a massive earthquake struck northeast Japan at 2:46 p.m. on March 11,
Fukushima Prefecture issued an evacuation directive at 9:00 p.m. to residents living
within a 2-km radius of the Fukushima-I Nuclear Power Station. The Fukushima-I-2
NPS suffered a loss of power from the electricity grid and is having to use backup
systems to moving water into its reactor cooling systems.
The reactor core still has a sufficient amount of water for cooling, with no danger of the
nuclear fuel being exposed. Several emergency generator vehicles have rushed to the
scene to provide the necessary power for the water supply.
At a press conference, Chief Cabinet Secretary Yukio Edano stressed that while there
was no confirmation of radiation leaking from the reactor, with sufficient time remaining
for its restoration, the government would direct residents living with a 3-km radius to
evacuate, and other residents living outside that limit but within a 10-km radius would be
urged to stand by at home.
Source: Federation of Electric Power Companies of Japan
 
The cooling system is now powerd by batteries i've just heard, because the emergency power generators are damaged. They have only some hours to repair it then it can explode if the batteries are empty...
 
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The cooling system is powerd by batteries i've just heard, because the emergency power generators are damaged. They have only some hours to repair it then it can explode...

As far as I can tell, the USA have already send an emergency response team (The reactor was build by a US company or based on a US BWR design) to the reactor with additional coolant. Not sure about the details how that should work if the circulation fails, but it is better as LOC. Also not sure how this team should get there, aircraft would have to land on the other side of the country, if I am not erring in the availability of undamaged airports.
 
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This is really horrible stuff. Some of the visuals they've been showing on the news are best described simply as scenes from a bad nightmare.

I've heard that they plan to release a small amount of vapour from the reactor to ease the pressure, and that this vapour is supposedly radioactive- clearly releasing vapour into the atmosphere is a better option than a total meltdown, but... what is the risk from this procedure?
 
I've just read, that they have some mobile power generator vehicles there, but they can't connect them because they don't have a cable.

In other circumstances this could be a good scetche in a comedy show, but i can't laugh about that today because it's real!

They are delivering a cable by aircraft... I Hope and pray that they are fast enogh!
 
Much worse: The US team does not bring coolant, but actually only a "tiny" cable that permits connecting the on-site mobile emergency power generators to the coolant pumps. The battery operation is required because of that problem. The problems with the emergency pumps seem also to be worse because many pumps and generators had been damaged by an earlier Earthquake years ago, without having been repaired yet.

It is a bright flashing red situation with claxons all over it.

If the battery power runs out before the cable is there, only natural circulation can cool the fuel, and this reactor was not designed for this, it is a feature of modern BWRs introduced after 1990. So temperatures and pressure will keep on rising rather quickly then.

A rule of thumb is (according to Mycle Schneider), that a reactor produces residual power of 7% of its design power. At 700 MW, this means 49 MW!

I've heard that they plan to release a small amount of vapour from the reactor to ease the pressure, and that this vapour is supposedly radioactive- clearly releasing vapour into the atmosphere is a better option than a total meltdown, but... what is the risk from this procedure?

It is a BWR so all steam in the plant is contaminated. This contamination is mostly nitrogen with a half-life of 16 minutes, if the reactor fuel remains intact.

Worse is that lowering the pressure means more water evaporates and less coolant will remain in the pressure vessel. It brings you thus one step away from a pressure vessel failure but one step closer to a melt-down.
 
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Worse is that lowering the pressure means more water evaporates and less coolant will remain in the pressure vessel. It brings you thus one step away from a pressure vessel failure but one step closer to a melt-down.
What's worse? A pressure vessel failure would pulverise the already present content and leave the open gap for the worse stuff that would follow the imminent meltdown.
Preventing the breach could cause a meltdown, which would, as far as i understand, merely destroy the plant. Or is there a chance of america syndrome there?
 
The vents are open now to blow out contaminated air...
I think that this is one of their last steps in their emergency procedure before the meltdown would happent...
 
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Kind of makes me happy that I work at a PWR.
I wonder if they have that goofy rod insertion/extration method that our BWR at Browns Ferry use. Their rods are beneath the reactor, whereas ours are above (gravity is our friend in a worst-case).
 
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