Video: Japan - Nuclear plant explosion

[thermodynamics]

Grrrrreat......Unit 2 at Fukushima Daiichi just exploded. It's a hydrogen explosion just like units 1 & 3, with the same consequences.

 

[metta]

Japanese agency: Explosion heard at nuclear plant

A third explosion in four days rocked the earthquake-damaged Fukushima Dai-ichi nuclear plant in northeast Japan early Tuesday, the country's nuclear safety agency said.

http://news.yahoo.com/s/ap/20110315/ap_on_bi_ge/as_japan_earthquake_nuclear_crisis



I just heard on the news that there are medicines that can be used to help people that have been exposed to too much radiation. They can sometimes reduce the radiation within days.

 

[thermodynamics]

Japanese agency: Explosion heard at nuclear plant




http://news.yahoo.com/s/ap/20110315/ap_on_bi_ge/as_japan_earthquake_nuclear_crisis



I just heard on the news that there are medicines that can be used to help people that have been exposed to too much radiation. They can sometimes reduce the radiation within days.

Potassium Iodide is given to large populations (especially children) that may be exposed to low level radiation. It prevents thyroid cancer. The thyroid fulfills its "need" for iodine by drawing in the potassium iodide, instead of radioactive iodine through the environment.

There are several other medications that will bind to the heavy atoms of radioactive elements and then get excreted in bodily waste.

 

[thermodynamics]

Grrrrreat......Unit 2 at Fukushima Daiichi just exploded. It's a hydrogen explosion just like units 1 & 3, with the same consequences.

Initial reports (have not been corroborated by TEPCO press release) suggested that the reactor vessel was damaged, but more recent reports deny this. In addition, the reactor's suppression pool is very likely damaged. This isn't a part of the primary containment, but it does hold a lot of water that is normally only slightly radioactive. Whenever they release pressure from the reactor vessel (not talking about the containment here) the steam is routed to the suppression pool where the steam condenses back to water. But because there is almost certainly fuel rod damage, fission products (normally contained within the fuel rods) will be in the water.

In addition the dose rate of radiation at the plant right after the explosion was far higher then it's ever been in this accident at 8217 microSieverts/hour. It's since dropped to around 1900 microSieverts/hr. The annual dose limit for plant workers is 1000 microSieverts.

I haven't been too concerned throughout this entire incident. With these initial reports from unit 2, I'm definitely concerned. The initial reports could very well be wrong.

 

[Telstra]

more bad news.
Reactor 4 is on fire and high radiation detected.

 

[metta]

How a Reactor Shuts Down and What Happens in a Meltdown

http://www.nytimes.com/interactive/...plosion-at-the-japanese-reactor.html?ref=asia

 

[ChickenGuy]

The situation with this nuclear plant seems to be rapidly deteriorating.


First of all, three days ago, reactor #1 exploded....




And then, yesterday, reactor #3 exploded....




And now just within the last few hours, reactor #2 has exploded. (no video yet)

And a fire has just broken out at reactor #4 but it has apparently been extinguished.

You wonder what is going to happen next.

 

[briefs4me]

^ the reactors did not explode....just the containment buildings.

 

[Telstra]

thermodynamics,
the news is very bad now. Your thoughts ?

According to Greenpeace it is as serious as Chernobyl

 

[metta]

TEPCO releases photo of No.4 reactor

The photo, shot the day before from the northwestern side of the reactor, shows that a large portion of the building's outer wall has collapsed. There is an 8-meter hole on the 4th floor, and the interior is visible.

Another 8-meter square hole was also confirmed on the outer wall of the building. Both appeared after an explosion early on Tuesday.

http://www3.nhk.or.jp/daily/english/16_25.html

 

[Jayden]

[ame]http://www.youtube.com/watch?v=7MR7u8xSr-8[/ame]

 

[metta]

^
That reminds me of the rains that we had in 2004/5. We had our 100 year flood and I live in a pretty risky area, next to a forest, with a river and creek that goes by. There are at least 3 old dams above us and if the dams ever broke, most of the development that I live in would be under water. Actually if they ever broke, I was told that many cities would be under water all the way down to the Ocean, a 35 mile stretch. I was told...don't know if it is true, that my home is above the flood zone. It was wild to see and hear the power of nature. The gentle river turned into something that seemed out of control. They had to release the water from the dams to protect them and you could see huge trees and boulders bigger than small cars going down the river. When the water subsided, we saw the erosion of the soil in the riverbed created a cliff from the erosion in some places that was more than 20 feet deep. I was amazed that was possible from one season of rain. I have to cross a bridge to get to the development that I live in. Thankfully, the city required them to build the bridge down to the bedrock. The steel/cement bridge would have probably been washed out if it was not for that. Even 6 years later, the river has not recovered. We went from a sandy riverbed with lots of plants and moss to a rocky one. It will be interesting to see what it looks like at the bottom this summer, when they stop the water. With the forest fires that we have had, I think that brought a lot of sandy/dirty water down...I'm hoping that some of it will stay in the riverbed.

 

[briefs4me]

thermodynamics,
the news is very bad now. Your thoughts ?

According to Greenpeace it is as serious as Chernobyl

In my opinion, Greenpeace are a bunch of idiots.

Chernobyl was an RMBK designed reactor. It used graphite as a moderator. This was a very poor design and very poorly constructed. These types of reactors were very unstable at low power which is exactly what the status of the reactor when it exploded.

All of the plants in the US, Japan, and throughout the world use water as a moderator. If the fuel is exposed, the temperatures will rise and the fuel will begin to melt. This is what happened at Three Mile Island. There was radiation that was leaked. The amount of radiation that leaked was 400 mRem (millirem) which the same amount everyone living picks up from background radiation in a year. You have to be exposed to an acute dose of 25,000 mRem before there are any health effects.

Fukushima is a Boiling Water Reactor. The explosions there ere from hydrogen and only the containment buildings were destroyed. All of the reactors survived 3 minutes of shaking from a 9.0 eathquake and the tsunami afterwards. The cooling systems are what failed because they were knocked out during the quake and the backup diesel generators were knocked out by the tsunami.

It is a terrible tragedy but all of the reactors remain intact. These reactors can withstand temperatures of 5,000 degrees Farenheit with core meltdown occurring at 3,000 degrees.

Therefore this event is nowhere near as bad as Chernobyl. They aren't even in the same league. The news media likes a story and keeps relating this to Chernobyl when they are like comaring apples to oranges.

 

[Daximus]

Think of all the people over there. It's frickin winter time from what I've seen and 10's of thousands of people are homeless and you guys wanna have an intelligence pissing contest on the net.

 

[Telstra]

In my opinion, Greenpeace are a bunch of idiots.

Chernobyl was an RMBK designed reactor. It used graphite as a moderator. This was a very poor design and very poorly constructed. These types of reactors were very unstable at low power which is exactly what the status of the reactor when it exploded.

All of the plants in the US, Japan, and throughout the world use water as a moderator. If the fuel is exposed, the temperatures will rise and the fuel will begin to melt. This is what happened at Three Mile Island. There was radiation that was leaked. The amount of radiation that leaked was 400 mRem (millirem) which the same amount everyone living picks up from background radiation in a year. You have to be exposed to an acute dose of 25,000 mRem before there are any health effects.

Fukushima is a Boiling Water Reactor. The explosions there ere from hydrogen and only the containment buildings were destroyed. All of the reactors survived 3 minutes of shaking from a 9.0 eathquake and the tsunami afterwards. The cooling systems are what failed because they were knocked out during the quake and the backup diesel generators were knocked out by the tsunami.

It is a terrible tragedy but all of the reactors remain intact. These reactors can withstand temperatures of 5,000 degrees Farenheit with core meltdown occurring at 3,000 degrees.

Therefore this event is nowhere near as bad as Chernobyl. They aren't even in the same league. The news media likes a story and keeps relating this to Chernobyl when they are like comaring apples to oranges.

according to logic,
the nuclear reaction is continuing for a very long time right?

How are they going to fix the containment buildings if the nuclear reaction is continuing (almost forever). You can't change a car tyre if temperature will burn you every time you go near it.

 

[thermodynamics]

according to logic,
the nuclear reaction is continuing for a very long time right?

How are they going to fix the containment buildings if the nuclear reaction is continuing (almost forever). You can't change a car tyre if temperature will burn you every time you go near it.

While the media's running around in circles on this...

What likely occured is that the spent fuel pool water level in unit 4 got too low and exposed the tops of the fuel rods in the pool. Note that we're not talking about the core of any of the reactors here. We're talking about the spent fuel pool--a swimming pool for the spent fuel to cool down in. The exposed portion of the fuel got too hot, and melted the zirconium fuel rod cladding. Because it was so hot the zirconium also oxidized with the water vapor/steam around the spent fuel pool. This created hydrogen gas (highly flammable) which eventually caught fire. The fire went out when there was no longer any hydrogen to burn. This has now happened twice at unit 4.

Normally the spent fuel pool is kept cool with pumps and heat exchangers. But they don't have any electricity on site. In this case it's perfectly legitimate to simply let the pool water boil on its own because steam carries away an enormous amount of heat. The flipside is that the water must be added to the pool on a regular basis. The operators have been unable to do this. In addition to keeping the spent fuel cool the water also acts as a very good radiation shield.

The increased radiation during the fire is because of the damage to the fuel rods in the spent fuel pool. Whenever the zirconium cladding melts, some of the radioactive fission products release radiation into whatever is around the rods. Normally that's the water that surrounds the core or the spent fuel pool. But in this case, the release was directly into the atmosphere. Definitely not good. This caused the workers to completely evacuate the plant. But now the radiation levels have dropped significantly and they will be returning soon.

The "long" term fix for the containment buildings is this: Get the spent fuel pool filled with water again. This brings down the radiation down to a safe level around the spent fuel pool. Rebuild the roof and short sidewalls of the reactor building (they're actually blast walls). The top portion of the reactor buildings that blew apart are actually sacrificial and don't do anything to keep stuff "in." They only keep stuff "out" (rain, seagulls, ...).

The heat that is still being generated in the core (even though it's "shutdown") and in the spent fuel pool is called residual heat. It's from the radioactive decay of the fission products that are in the fuel. The core is actually producing about 5% of its rated power even though it's shutdown. There's a dedicated system in a reactor to deal with this. It's called the residual heat removal system (creative, yeah), but it's not functional because they don't have electric power.

 

[briefs4me]

according to logic,
the nuclear reaction is continuing for a very long time right?

How are they going to fix the containment buildings if the nuclear reaction is continuing (almost forever). You can't change a car tyre if temperature will burn you every time you go near it.

The reaction stopped when all of the control rods were inserted. This happened the instant the earthquake started. The rods are actually attached to control rod blades which are filled with boron. Boron stops the reaction. The problem is with the decay heat. All of the reactors shutdown when sensors indicated vibrations the instant the earthquake struck.

 

[thermodynamics]

Lovely...

Now that our guys from the NRC (Nuclear Regulatory Commission) have seen everything in Japan, they're saying things are worse than the Japanese had thought. NRC Chair Press Conference

The NRC believes (and I trust them far more than the Japanese) that there is no water at all in the spent fuel pool at reactor 4. That's got "dangerous radiation release to the public" written all over it. Not only does the water serve as a very effective radiation shield, it also keeps the spent fuel cool. If the spent fuel overheats, the zirconium cladding will melt and allow the fuel pellets to be exposed to the atmosphere.

Things are going from bad to worse in a hurry. I may have seemed cavalier about the situation a few days ago. At that time my attitude made sense. But this is a whole new can of worms.

 

[briefs4me]

Honestly, I believe that the Japanese gov't hasn't told everyone the scale of the disaster at Fukushima. I think they are afraid to say just how bad it is. Hopefully things can be brought under control soon. It's a real tragedy for a great country and the wonderful Japanese people.

 

[SLOPPYSECONDS]

Honestly, I believe that the Japanese gov't hasn't told everyone the scale of the disaster at Fukushima. I think they are afraid to say just how bad it is. Hopefully things can be brought under control soon. It's a real tragedy for a great country and the wonderful Japanese people.

whens any ( government&Co no matter what pants wear ) says a naythin whens it matter

or many populations ever BOTHER go find out what is goin on ins a theirs a own country world ova

18th century with lot toys and bits paper ta say they can play with da world as wish

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thankyou