Japan Earthquake and Tsunami (March 11, 2011)

[Jinto]

Originally Posted by Tri-ring

There was a minor melt down at the Fukushima No.1 plant No.1 reactor rupturing the outer casing at the top of one or more rods.Radioactive material Cesium had been detected outside the building.
The authorities does not know the scale nor severity of the explosion but reports that 1015 micro SEV had been measured around the building.
An evacuation notice had been issued 10Km radius from the plant and also ask for people within 15Km to do the same as precautionary measures.

What is SEV, is it Sv (sievert) by conincidence? If so, you cannot say directly if it is really bad if you do not know the time. Since natural background radiatian is typically 2.4 milli Sv/year (so 1 milli Sv in just one day, means you have already half a year worth of natural radiation consumed). So it would be interesting to know the time in which this dosis was measured. And what type of radiation, Alpha particles are considered 20 times more dangerous than beta particles of the same energy for example.

[RRW]

Japan has asked Britain for help in the aftermath of the earthquake, Britain's Foreign Office said.

[Tri-ring]

First of all fission reaction is under control since they rammed in the carbon control rods that absorbs neutrons required for fission reaction.
The reason why there is a melt down is because the fuel rods are exposed out of water and excess heat when it was still active has not dissipated. There are also radioactive material created through fission reaction which has a short half life. These radioactive material decays releasing alpha ray, bata ray and also generates heat. Once the fuel rods are covered in water it will cool down since it also slows down those sub atomic particles.

[Tri-ring]

Originally Posted by Jinto

What is SEV, is it Sv (sievert) by conincidence? If so, you cannot say directly if it is really bad if you do not know the time. Since natural background radiatian is typically 2.4 milli Sv/year (so 1 milli Sv in just one day, means you have already half a year worth of natural radiation consumed). So it would be interesting to know the time in which this dosis was measured. And what type of radiation, Alpha particles are considered 20 times more dangerous than beta particles of the same energy for example.

Yup, sievert. The time is per minute.
Do not have the type of sub-atomic particles had been measured.

[chaos_animagic]

Originally Posted by Tri-ring

First of all fission reaction is under control since they rammed in the carbon control rods that absorbs neutrons required for fission reaction.
The reason why there is a melt down is because the fuel rods are exposed out of water and excess heat when it was still active has not dissipated. There are also radioactive material created through fission reaction which has a short half life. These radioactive material decays releasing alpha ray, bata ray and also generates heat. Once the fuel rods are covered in water it will cool down since it also slows down those sub atomic particles.

Problem with that...

Is they failed at putting water in...
Because even tho they pump water in, it's leaking out somewhere and the water level is decreasing.
Thus revealing the rod to air.

It's 2:08am now... I am gonna go to sleep... >_<

[haegar]

Originally Posted by chaos_animagic

Problem with that...

Is they failed at putting water in...
Because even tho they pump water in, it's leaking out somewhere and the water level is decreasing.
Thus revealing the rod to air.

and that happend hours ago. and what little remained of the coolant liquid was turned into steam with so high a pressure that it blew the whole thing outwards. and there is no point in just putting in more water now. the pipes will be gone. what they can do, is pour down tons of concrete on it as they did in tchenobyl. that is however very difficult because of the immense heat. btw, tv says the just have increased the evac zone to 20 kilometers

[RRW]

The U.N. nuclear watchdog said it is aware of media reports of an explosion on Saturday at Japan's Fukushima No.1 nuclear power plant and is urgently seeking information from the country's authorities.

Evacuation radius at Fukushima nuclear plant has been increased to 20 km - TV

"This is starting to look a lot like Chernobyl" Walt Patterson, an associate fellow with Chatham House, has told the BBC after seeing pictures of the explosion at the Fukushima-Daiichi nuclear plant. "The nuclear agency says that they have detected caesium and iodine outside the unit, which certainly indicates fuel melting at the very least," he says. "Once you have melting fuel coming into contact with water, that would almost certainly be the cause of the explosion."

More from Walt Patterson of Chatham House. He says the presence of the radioactive caesium in the surrounding area does not pose a huge threat to public health in the immediate aftermath of the explosion. "What would be serious is if there was an explosion or fire that lifted this stuff high in the air, meaning it could get carried over a wide area."

[haegar]

Originally Posted by rrw

The U.N. nuclear watchdog said it is aware of media reports of an explosion on Saturday at Japan's Fukushima No.1 nuclear power plant and is urgently seeking information from the country's authorities.

Evacuation radius at Fukushima nuclear plant has been increased to 20 km - TV

"This is starting to look a lot like Chernobyl" Walt Patterson, an associate fellow with Chatham House, has told the BBC after seeing pictures of the explosion at the Fukushima-Daiichi nuclear plant. "The nuclear agency says that they have detected caesium and iodine outside the unit, which certainly indicates fuel melting at the very least," he says. "Once you have melting fuel coming into contact with water, that would almost certainly be the cause of the explosion."

and the comparison to Chernobyl is not because of radiation level (they don't know that yet, and yes due to light water it MIGHT be lower) but because the turn of events and result for reactor chamber/site are the same: after explosion, building structure is gone, resulting in the radiactive material left inside being open, unprotected keeping to radiate out. they will have to seal it, and fast. And still no news on the other blocks which were in very simmilar condition prior to explosion :/

[RRW]

The BBC's environment correspondent Roger Harrabin says he understands the blast at the nuclear plant may have been caused by a hydrogen explosion - also one of the possibilities laid out by Walt Patterson of Chatham House. "If nuclear fuel rods overheat and then come into contact with water, this produces a large amount of highly-flammable hydrogen gas which can then ignite," our correspondent says.

.it sounds like the gov't is requesting a voluntary media blackout of the reactor that blew

From the BBC's Chris Hogg: "Driving through Ibaraki prefecture north east of Tokyo it's clear vast swathes have no power. There are long queues at the few petrol stations openn as we approach the worst affected part of the prefecture. Presumably that's for fuel for generators. We're starting to see the first signs of damage. It's taken six hours to make a journey that should take an hour or so. The highways are off limits to all but emergency vehicles, the police told us."

[Jinto]

Originally Posted by chaos_animagic

Problem with that...

Is they failed at putting water in...
Because even tho they pump water in, it's leaking out somewhere and the water level is decreasing.
Thus revealing the rod to air.

It's 2:08am now... I am gonna go to sleep... >_<

Well, if the primary (inner) closed cycle cooling system is leaking, they'll have a serious problem with containing the radioactivity anyway. If the fuel rods are broken it means the coolant might be contaminated with the fuel itself (typically elements with a very long radioactive half-life) instead of just radioactively activated water (higher levels of tritium/deuterium in H2O).

@rrw,

for example Zr + 2 H2O => ZrO2 + 2 H2 (at 900°C) ... typically the reactor chambers are flooded with nitrogen in such an event to prevent the mixing of H2 and O2 into oxyhydrogen, however if the containment chamber is not sealed, the denser ("heavier") nitrogen will flow out and be replaced by instreaming air (which contains O2).

[solomon]

Sigh, 1,000 lost now according to NHK.

NHK says primier order came out magnifying Fukushima evacuation radius to 20 kilometers.

[Tyabann]

Originally Posted by rrw

.it sounds like the gov't is requesting a voluntary media blackout of the reactor that blew

Which means it's very, very bad.

I really hope they're doing something.

[Decagon]

Google map link of the Fukushima I power plant's location if anyone was curious about what is around it. This day has been very surreal.

[Patriot's Blade]

i hope the hyper rescue units are doing their best

[RRW]

Ok, they've changed the evac area, Plant 1 is 20 km Plant 2 is 10km.

Sayaka Matsumoto, from the Red Cross in Tokyo, says the organisation has sent more than 60 medical teams - some 450 doctors and nurses - to the worst-hit area. Those who have arrived in Sendai have opened a tent clinic in front of the city's main government building, she tells the BBC.

Japan nuclear authorities say pressure was successfully released at Fukushima plant by opening valves.

Japanese authorities say troops found between 300 and 400 bodies in the coastal city of Rikuzentakata, which was devastated by the tsunami

[haegar]

Originally Posted by rrw

Japan nuclear authorities say pressure was successfully released at Fukushima plant by opening valves.

'NHK world jap' has been confirming that, however they ALSO for the first time spoke of high temps and fuel rods melting DESPITE the efforts to reduce pressure and to cool. they also say the 4 workers injured on media before got injured when trying to open an exhaust valve that was exposed to high radiation. and that they had to abort attempt.

[Tri-ring]

I would like to note that there people working around the clock jeopardizing their lives trying to remedy the situation at Fukushima No.1 and No.2 nuclear power plants.
I also like to warn people not to make it a political issue using this incident to say no to nuclear power.
The earthquake which triggered the incident is a once in a thousand years event, the plants were constructed in 1970 and been in operation for the last 40 years without a problem.

[Malkuth]

Originally Posted by Tri-ring

I would like to note that there people working around the clock jeopardizing their lives trying to remedy the situation at Fukushima No.1 and No.2 nuclear power plants.
I also like to warn people not to make it a political issue using this incident to say no to nuclear power.
The earthquake which triggered the incident is a once in a thousand years event, the plants were constructed in 1970 and been in operation for the last 40 years without a problem.

I completely agree.

[haegar]

Originally Posted by Tri-ring

I would like to note that there people working around the clock jeopardizing their lives trying to remedy the situation at Fukushima No.1 and No.2 nuclear power plants.
I also like to warn people not to make it a political issue using this incident to say no to nuclear power.

up to about here this is an unbiased neutral statement.

The earthquake which triggered the incident is a once in a thousand years event, the plants were constructed in 1970 and been in operation for the last 40 years without a problem.

on this, one can say "right back at ya mr.supporter" 0.o I suggest you do some research and consider modifying your position of "without a problem" I also suggest you not pretend to be neutral while INFACT bein the opposite and likewise do not pretend to tell people NOT to go into that kinda political topic while YOU happen to be the one doing EXACTLY that.

So far EXCEPT for YOU - NOBODY went into politics, we all are just worried very much in short ... go take that somewhere else please, thank you very much :/

[RRW]

Japan's Nuclear and Industrial Safety Agency says serious damage to the nuclear reactor container is unlikely despite the explosion at the Fukushima-Daiichi plant - Kyodo news.

Spoiler for .: