Video: Japan - Nuclear plant explosion

[gsdx]

The tsunami travelled 4 km inland, washing away thousands of cars and homes, and even 4 trains. One small town lost over 9,000 people - more than half its population. http://ca.news.yahoo.com/rescue-efforts-gear-devastated-japan-20110312-012935-154.html

They didn't need this explosion as well:

http://ca.news.yahoo.com/video/worl...-pours-from-japan-nuclear-plant-24499891.html

 

[looseliam]

I read they had to vent something to relieve pressure - releasing radiation into the air. I guess it was better than the alternative.

 

[thermodynamics]

They had to release built up steam in the reactor vessel to prevent a steam explosion.

But then...

The water level dropped in the reactor vessel because the coolant pumps weren't operating (diesel generator was lost to the tsunami). The level dropped enough to begin to expose the zirconium fuel casings (which holds the uranium) to steam. At high temperatures the steam reacts with the zirconium to produce zirconium oxide (inconsequential) and hydrogen gas (which can explode). They vented the steam/hydrogen mix into the containment building, then out to the atmosphere, hoping to avoid an explosion. It didn't work, and kaboom! The containment building exploded/collapsed. The reactor vessel (RPV) remained intact (whew!), but now there's no backup structure to contain any radiation releases. The Fukushima reactors are boiling water reactors (BWR). Here's the wiki page: http://en.wikipedia.org/wiki/Boiling_water_reactor

Note that the gray enclosure around everything is the containment vessel

 

[Scottyboi]

omg i about had a panic attack when i saw this thread title, I thought the reactor had finally reached the point where they couldn't cool it anymore and it had gone "Chernobyl" on us

 

[Spiff]

omg i about had a panic attack when i saw this thread title, I thought the reactor had finally reached the point where they couldn't cool it anymore and it had gone "Chernobyl" on us

That is what all the big media is currently doing. Rather than provide us with a proper explanation like thermodymanics has (thanks, therm).

Interesting that this plant was designed by General Electric.

 

[Snuffy]

For some reason I had the impression that the Japanese were so advanced that they would have planned for something like this and meltdowns would be impossible.

 

[thermodynamics]

I just read a NY Times article that sheds a tiny bit more info on what happened in the explosion, but does more to show off the ignorance of the reporter when it comes to nuclear reactors. The words are "containment" and "reactor pressure vessel". I hate it when reporters try to tell sciencey stories...they have a terrible record at getting it all wrong.

If I were living close to the plant, I wouldn't worry.

A word (OK, a few) about Chernobyl...
The RBMK (Chernobyl) reactor design was stupid. First, it had no containment structure. That's the big, thick, concrete structure designed to contain radiation in an accident. Second, more importantly, it had a positive void coefficient--a vicious cycle. In short, when the core water level dropped, the reaction sped up and created more heat. This causes the water level to drop more, and, well, you get the picture... This is in contrast to any other design which has a negative void coefficient. In these plants the reaction slows down and creates less heat when the core water level drops. ALL U.S. reactors must have negative void coefficents.

 

[looseliam]

thanks thermo! I always like to know a bit of the nitty-gritty behind the shinny pictures =]

 

[HugoB]

75 years ago

´


Because of the topical inducement:


Back to the year 1936 and . 'The Invisible Ray'


A visionary and radiating thriller with Bela Lugosi & Boris Karloff:

http://en.wikipedia.org/wiki/The_Invisible_Ray_(1936_film)




Here to the trailer: [ame]http://www.youtube.com/watch?v=t_gsfQS7oxY[/ame]



The complete version:

[ame]http://www.youtube.com/watch?v=a-B9e_aNu6s[/ame]


´

 

[metta]

For battered Japan, a new threat: nuclear meltdown

"A partial meltdown was likely under way at a second nuclear reactor, a top Japanese official said Sunday, as authorities frantically tried to prevent a similar threat from nearby unit following a catastrophic earthquake and tsunami."

http://news.yahoo.com/s/ap/20110313/ap_on_bi_ge/as_japan_earthquake


There has been a recent push for more nuclear plants to be built in the US, including a push from some environmentalists. I wonder if that will change from all of this.

Seeing what an earth quake can do to a nuclear plant with 5 backup supplies that all failed after the earthquake, it makes me wonder If a nuclear plant was ever attached by another country or terrorist, how dangerous could that be?

 

[thermodynamics]

Meltdown...not at all likely at this point. The media has gotten most of it wrong. I found the forum site nukeworker.com. These are the guys who operate U.S. reactors. They're not too concerned. They've read media reports (and laughed a lot) and the TEPCO press releases (which make a lot more sense than the media reports).

The 9AM press release from TEPCO Tepco Press Releases indicates there's still an issue with core cooling at the Fukushima Daiichi 3 reactor. The High Pressure Core Injection system shut down for an unknown reason. There's still plenty of ways to cool the core, especially this far out in time from the earthquake and initial shutdown.

 

[thermodynamics]

Here's some light reading material:

NRC BWR Reactor Concepts Manual

 

[HugoB]

^primitive mechanical components. Not even one ICC in sight.
Where's the curl generator?

Parts of the scenery and laboratory of 'The Invisible Ray'
are from 'Frankenstein' (1931) and 'Flash Gordon'.


Four more atomic ads from the fifties.... and a special vision...
´

 

[star-warrior]

I wonder if they've sent people into the plant to take care of things or whether it's all done remotely. If there were folks near it when the place exploded.... I can't see they dare send people into the now malfunctioning Fukushima no.3 reactor...

 

[HugoB]

´

Not to forget 'The Atomic Cafe' (1982).


A documentary of the US nuclear propaganda in the fourties & fifties...


................................................ http://www.imdb.com/title/tt0083590/




[ame]http://www.youtube.com/watch?v=RHGa9nUbDww[/ame]

 

[Telstra]

wow, nuclear disaster crisis ..............

http://www.abc.net.au/news/stories/2011/03/13/3162802.htm?section=world

 

[briefs4me]

I work for GE Nuclear. We had some of our guys over there when the quake hit. They were working on reactor number 4. I like how the media keeps relating this to Chernobyl. This reactor design will not "blow up". Meltdown is possible but without any major health risks to the public. The reactor is housed in 6 inches of steel and even more concrete surrounding it. The explosion was a buildup of hydrogen gas that combined with oxygen. The pressure was too great and it had to go somewhere. Thermo has his facts correct. While this is a major disaster, loss of life from it is pretty much nil. Nuclear power is safe. Look at how many people were killed from nuclear plants and then look at other plants, coal, gas, oil, etc. It is scary stuff but it is still safe.

 

[thermodynamics]

I work for GE Nuclear. We had some of our guys over there when the quake hit. They were working on reactor number 4. I like how the media keeps relating this to Chernobyl. This reactor design will not "blow up". Meltdown is possible but without any major health risks to the public. The reactor is housed in 6 inches of steel and even more concrete surrounding it. The explosion was a buildup of hydrogen gas that combined with oxygen. The pressure was too great and it had to go somewhere. Thermo has his facts correct. While this is a major disaster, loss of life from it is pretty much nil. Nuclear power is safe. Look at how many people were killed from nuclear plants and then look at other plants, coal, gas, oil, etc. It is scary stuff but it is still safe.

BINGO!

Sounds like they uncovered 3 meters of active core, but then covered it again. No word on fuel assembly damage though. Link I've been telling people I've seen in the last few days that it's not nearly as bad as the media makes it out to be. The Soviets were just plain stupid when they came up with the RBMK design. Who in their right mind designs and then builds a plant with 1. No containment structure, and 2. a positive void coefficient?

 

[star-warrior]

I work for GE Nuclear. We had some of our guys over there when the quake hit. They were working on reactor number 4. I like how the media keeps relating this to Chernobyl. This reactor design will not "blow up". Meltdown is possible but without any major health risks to the public. The reactor is housed in 6 inches of steel and even more concrete surrounding it. The explosion was a buildup of hydrogen gas that combined with oxygen. The pressure was too great and it had to go somewhere. Thermo has his facts correct. While this is a major disaster, loss of life from it is pretty much nil. Nuclear power is safe. Look at how many people were killed from nuclear plants and then look at other plants, coal, gas, oil, etc. It is scary stuff but it is still safe.

BINGO!

Sounds like they uncovered 3 meters of active core, but then covered it again. No word on fuel assembly damage though. Link I've been telling people I've seen in the last few days that it's not nearly as bad as the media makes it out to be. The Soviets were just plain stupid when they came up with the RBMK design. Who in their right mind designs and then builds a plant with 1. No containment structure, and 2. a positive void coefficient?

Thanks guys for providing accurate information in the face of media sensationalism. I guess the old addage "never let the truth get in the way of a good story" applies, sensationalism keeps the readers/viewers gripped for more...

 

[briefs4me]

The media has all these "experts" commenting and they have no idea how these reactors are designed. The Japanese should have been filling the containment with sea water long before the pressure built up. Cool the thing down, then do damage assessment...Just my 2 cents!