Earthquake Japan

[XR6_661]

Originally Posted by news.com.au

1.56pm 2000 bodies have been found on the shores of the Miyagi prefecture. 1000 washed ashore at Miyagi's Ojika Peninsula, and another 1000 were seen at the town of Minamisanriku, where over 10,000 were earlier reported missing.

This is just off the hook...

[ratter]

Delete

[XR6_661]

Originally Posted by ratter

according to the news, not an explosion but a landslide, what a load of crap

Bit hard to call it a landslide when there is video footage of the bloody thing blowing up.

[ratter]

Yeah exactly, but the news then reported that there was not another earthquake, it was the landslide, so not sure if I heard incorrectly the first time about the explosion being a landslide

[cheap]

Originally Posted by charles_wif_xf

It looked massive compared to the first one. I hope that it's only the containment building and not the containment vessel and/or core.

The link below will not go well with the ka-boom, imminent world-is-ending people. If anyone cares to be a little more informed read on:

http://bravenewclimate.com/2011/03/1...e-explanation/

[XR6_661]

That’s amazing engineering.

Building withstood a 8.9, 7 times stronger than what it’s designed for. That’s like a small dynabolted storage shed withstanding a cat 5 cyclone with no shielding.

[blueoval]

Originally Posted by charles_wif_xf

It looked massive compared to the first one. I hope that it's only the containment building and not the containment vessel and/or core.

the sky news and CNN were saying that it was a hydrogen explosion nothing more. Still, any explosions aren't good.

[galaxy xr8]

Originally Posted by cheap

The link below will not go well with the ka-boom, imminent world-is-ending people. If anyone cares to be a little more informed read on:

http://bravenewclimate.com/2011/03/1...e-explanation/

That was a very good read, thank's for that.

[Mickxr8]

Not sure if this should be posted here but..
I have a friend in the UK that put this up on his Youtube page.
Its basically an attack on all the dumb stuff getting put up on `social networking` sites.
http://www.youtube.com/watch?v=o98s2...&feature=feedu

WARNING Contains the "f" word.

[g220ba]

Originally Posted by cheap

The link below will not go well with the ka-boom, imminent world-is-ending people. If anyone cares to be a little more informed read on:

http://bravenewclimate.com/2011/03/1...e-explanation/

Thanks for that cheap. Great read, very informative and dispells alot of the myths and hype against nuclear power that we've seen in the last couple of days. Even with what can be described as worse case scenario the chances of serious radiation leaks are so low it's not even worth considering.

This whole situation has turned into a massive joke that is unfortunetly overshadowing the seriousness of what the people of japan are actually facing.

I recommend everyone take a couple of minutes and read the article cheap posted.

[tweeked]

Originally Posted by cheap

The link below will not go well with the ka-boom, imminent world-is-ending people. If anyone cares to be a little more informed read on:

http://bravenewclimate.com/2011/03/1...e-explanation/

Great article.

One thing is sure for me after this is all said and done, I will either change my mind and be against nuclear power even in a geologically stable place like Australia, or if these 40 year old western nuclear plants survive an 8.9 magnitude earthquake, a tsunami and these explosions with only very minimal radiation leaking, I will be totally for replacing all of Australia's power generation with nuclear.

[Road Games]

Originally Posted by cheap

The link below will not go well with the ka-boom, imminent world-is-ending people. If anyone cares to be a little more informed read on:

http://bravenewclimate.com/2011/03/1...e-explanation/

Construction of the Fukushima nuclear power plants

The plants at Fukushima are so called Boiling Water Reactors, or BWR for short. Boiling Water Reactors are similar to a pressure cooker. The nuclear fuel heats water, the water boils and creates steam, the steam then drives turbines that create the electricity, and the steam is then cooled and condensed back to water, and the water send back to be heated by the nuclear fuel. The pressure cooker operates at about 250 °C.

The nuclear fuel is uranium oxide. Uranium oxide is a ceramic with a very high melting point of about 3000 °C. The fuel is manufactured in pellets (think little cylinders the size of Lego bricks). Those pieces are then put into a long tube made of Zircaloy with a melting point of 2200 °C, and sealed tight. The assembly is called a fuel rod. These fuel rods are then put together to form larger packages, and a number of these packages are then put into the reactor. All these packages together are referred to as “the core”.

The Zircaloy casing is the first containment. It separates the radioactive fuel from the rest of the world.

The core is then placed in the “pressure vessels”. That is the pressure cooker we talked about before. The pressure vessels is the second containment. This is one sturdy piece of a pot, designed to safely contain the core for temperatures several hundred °C. That covers the scenarios where cooling can be restored at some point.

The entire “hardware” of the nuclear reactor – the pressure vessel and all pipes, pumps, coolant (water) reserves, are then encased in the third containment. The third containment is a hermetically (air tight) sealed, very thick bubble of the strongest steel. The third containment is designed, built and tested for one single purpose: To contain, indefinitely, a complete core meltdown. For that purpose, a large and thick concrete basin is cast under the pressure vessel (the second containment), which is filled with graphite, all inside the third containment. This is the so-called “core catcher”. If the core melts and the pressure vessel bursts (and eventually melts), it will catch the molten fuel and everything else. It is built in such a way that the nuclear fuel will be spread out, so it can cool down.

This third containment is then surrounded by the reactor building. The reactor building is an outer shell that is supposed to keep the weather out, but nothing in. (this is the part that was damaged in the explosion, but more to that later).

Fundamentals of nuclear reactions

The uranium fuel generates heat by nuclear fission. Big uranium atoms are split into smaller atoms. That generates heat plus neutrons (one of the particles that forms an atom). When the neutron hits another uranium atom, that splits, generating more neutrons and so on. That is called the nuclear chain reaction.

Now, just packing a lot of fuel rods next to each other would quickly lead to overheating and after about 45 minutes to a melting of the fuel rods. It is worth mentioning at this point that the nuclear fuel in a reactor can *never* cause a nuclear explosion the type of a nuclear bomb. Building a nuclear bomb is actually quite difficult (ask Iran). In Chernobyl, the explosion was caused by excessive pressure buildup, hydrogen explosion and rupture of all containments, propelling molten core material into the environment (a “dirty bomb”). Why that did not and will not happen in Japan, further below.

In order to control the nuclear chain reaction, the reactor operators use so-called “control rods”. The control rods absorb the neutrons and kill the chain reaction instantaneously. A nuclear reactor is built in such a way, that when operating normally, you take out all the control rods. The coolant water then takes away the heat (and converts it into steam and electricity) at the same rate as the core produces it. And you have a lot of leeway around the standard operating point of 250°C.

The challenge is that after inserting the rods and stopping the chain reaction, the core still keeps producing heat. The uranium “stopped” the chain reaction. But a number of intermediate radioactive elements are created by the uranium during its fission process, most notably Cesium and Iodine isotopes, i.e. radioactive versions of these elements that will eventually split up into smaller atoms and not be radioactive anymore. Those elements keep decaying and producing heat. Because they are not regenerated any longer from the uranium (the uranium stopped decaying after the control rods were put in), they get less and less, and so the core cools down over a matter of days, until those intermediate radioactive elements are used up.

This residual heat is causing the headaches right now.

So the first “type” of radioactive material is the uranium in the fuel rods, plus the intermediate radioactive elements that the uranium splits into, also inside the fuel rod (Cesium and Iodine).

There is a second type of radioactive material created, outside the fuel rods. The big main difference up front: Those radioactive materials have a very short half-life, that means that they decay very fast and split into non-radioactive materials. By fast I mean seconds. So if these radioactive materials are released into the environment, yes, radioactivity was released, but no, it is not dangerous, at all. Why? By the time you spelled “R-A-D-I-O-N-U-C-L-I-D-E”, they will be harmless, because they will have split up into non radioactive elements. Those radioactive elements are N-16, the radioactive isotope (or version) of nitrogen (air). The others are noble gases such as Xenon. But where do they come from? When the uranium splits, it generates a neutron (see above). Most of these neutrons will hit other uranium atoms and keep the nuclear chain reaction going. But some will leave the fuel rod and hit the water molecules, or the air that is in the water. Then, a non-radioactive element can “capture” the neutron. It becomes radioactive. As described above, it will quickly (seconds) get rid again of the neutron to return to its former beautiful self.

This second “type” of radiation is very important when we talk about the radioactivity being released into the environment later on.

What happened at Fukushima

I will try to summarize the main facts. The earthquake that hit Japan was 7 times more powerful than the worst earthquake the nuclear power plant was built for (the Richter scale works logarithmically; the difference between the 8.2 that the plants were built for and the 8.9 that happened is 7 times, not 0.7). So the first hooray for Japanese engineering, everything held up.

When the earthquake hit with 8.9, the nuclear reactors all went into automatic shutdown. Within seconds after the earthquake started, the control rods had been inserted into the core and nuclear chain reaction of the uranium stopped. Now, the cooling system has to carry away the residual heat. The residual heat load is about 3% of the heat load under normal operating conditions.

The earthquake destroyed the external power supply of the nuclear reactor. That is one of the most serious accidents for a nuclear power plant, and accordingly, a “plant black out” receives a lot of attention when designing backup systems. The power is needed to keep the coolant pumps working. Since the power plant had been shut down, it cannot produce any electricity by itself any more.

Things were going well for an hour. One set of multiple sets of emergency Diesel power generators kicked in and provided the electricity that was needed. Then the Tsunami came, much bigger than people had expected when building the power plant (see above, factor 7). The tsunami took out all multiple sets of backup Diesel generators.

When designing a nuclear power plant, engineers follow a philosophy called “Defense of Depth”. That means that you first build everything to withstand the worst catastrophe you can imagine, and then design the plant in such a way that it can still handle one system failure (that you thought could never happen) after the other. A tsunami taking out all backup power in one swift strike is such a scenario. The last line of defense is putting everything into the third containment (see above), that will keep everything, whatever the mess, control rods in our out, core molten or not, inside the reactor.

When the diesel generators were gone, the reactor operators switched to emergency battery power. The batteries were designed as one of the backups to the backups, to provide power for cooling the core for 8 hours. And they did.

Within the 8 hours, another power source had to be found and connected to the power plant. The power grid was down due to the earthquake. The diesel generators were destroyed by the tsunami. So mobile diesel generators were trucked in.

This is where things started to go seriously wrong. The external power generators could not be connected to the power plant (the plugs did not fit). So after the batteries ran out, the residual heat could not be carried away any more.

At this point the plant operators begin to follow emergency procedures that are in place for a “loss of cooling event”. It is again a step along the “Depth of Defense” lines. The power to the cooling systems should never have failed completely, but it did, so they “retreat” to the next line of defense. All of this, however shocking it seems to us, is part of the day-to-day training you go through as an operator, right through to managing a core meltdown.

It was at this stage that people started to talk about core meltdown. Because at the end of the day, if cooling cannot be restored, the core will eventually melt (after hours or days), and the last line of defense, the core catcher and third containment, would come into play.

But the goal at this stage was to manage the core while it was heating up, and ensure that the first containment (the Zircaloy tubes that contains the nuclear fuel), as well as the second containment (our pressure cooker) remain intact and operational for as long as possible, to give the engineers time to fix the cooling systems.

Because cooling the core is such a big deal, the reactor has a number of cooling systems, each in multiple versions (the reactor water cleanup system, the decay heat removal, the reactor core isolating cooling, the standby liquid cooling system, and the emergency core cooling system). Which one failed when or did not fail is not clear at this point in time.

So imagine our pressure cooker on the stove, heat on low, but on. The operators use whatever cooling system capacity they have to get rid of as much heat as possible, but the pressure starts building up. The priority now is to maintain integrity of the first containment (keep temperature of the fuel rods below 2200°C), as well as the second containment, the pressure cooker. In order to maintain integrity of the pressure cooker (the second containment), the pressure has to be released from time to time. Because the ability to do that in an emergency is so important, the reactor has 11 pressure release valves. The operators now started venting steam from time to time to control the pressure. The temperature at this stage was about 550°C.

This is when the reports about “radiation leakage” starting coming in. I believe I explained above why venting the steam is theoretically the same as releasing radiation into the environment, but why it was and is not dangerous. The radioactive nitrogen as well as the noble gases do not pose a threat to human health.

At some stage during this venting, the explosion occurred. The explosion took place outside of the third containment (our “last line of defense”), and the reactor building. Remember that the reactor building has no function in keeping the radioactivity contained. It is not entirely clear yet what has happened, but this is the likely scenario: The operators decided to vent the steam from the pressure vessel not directly into the environment, but into the space between the third containment and the reactor building (to give the radioactivity in the steam more time to subside). The problem is that at the high temperatures that the core had reached at this stage, water molecules can “disassociate” into oxygen and hydrogen – an explosive mixture. And it did explode, outside the third containment, damaging the reactor building around. It was that sort of explosion, but inside the pressure vessel (because it was badly designed and not managed properly by the operators) that lead to the explosion of Chernobyl. This was never a risk at Fukushima. The problem of hydrogen-oxygen formation is one of the biggies when you design a power plant (if you are not Soviet, that is), so the reactor is build and operated in a way it cannot happen inside the containment. It happened outside, which was not intended but a possible scenario and OK, because it did not pose a risk for the containment.

So the pressure was under control, as steam was vented. Now, if you keep boiling your pot, the problem is that the water level will keep falling and falling. The core is covered by several meters of water in order to allow for some time to pass (hours, days) before it gets exposed. Once the rods start to be exposed at the top, the exposed parts will reach the critical temperature of 2200 °C after about 45 minutes. This is when the first containment, the Zircaloy tube, would fail.

And this started to happen. The cooling could not be restored before there was some (very limited, but still) damage to the casing of some of the fuel. The nuclear material itself was still intact, but the surrounding Zircaloy shell had started melting. What happened now is that some of the byproducts of the uranium decay – radioactive Cesium and Iodine – started to mix with the steam. The big problem, uranium, was still under control, because the uranium oxide rods were good until 3000 °C. It is confirmed that a very small amount of Cesium and Iodine was measured in the steam that was released into the atmosphere.

It seems this was the “go signal” for a major plan B. The small amounts of Cesium that were measured told the operators that the first containment on one of the rods somewhere was about to give. The Plan A had been to restore one of the regular cooling systems to the core. Why that failed is unclear. One plausible explanation is that the tsunami also took away / polluted all the clean water needed for the regular cooling systems.

The water used in the cooling system is very clean, demineralized (like distilled) water. The reason to use pure water is the above mentioned activation by the neutrons from the Uranium: Pure water does not get activated much, so stays practically radioactive-free. Dirt or salt in the water will absorb the neutrons quicker, becoming more radioactive. This has no effect whatsoever on the core – it does not care what it is cooled by. But it makes life more difficult for the operators and mechanics when they have to deal with activated (i.e. slightly radioactive) water.

But Plan A had failed – cooling systems down or additional clean water unavailable – so Plan B came into effect. This is what it looks like happened:

In order to prevent a core meltdown, the operators started to use sea water to cool the core. I am not quite sure if they flooded our pressure cooker with it (the second containment), or if they flooded the third containment, immersing the pressure cooker. But that is not relevant for us.

The point is that the nuclear fuel has now been cooled down. Because the chain reaction has been stopped a long time ago, there is only very little residual heat being produced now. The large amount of cooling water that has been used is sufficient to take up that heat. Because it is a lot of water, the core does not produce sufficient heat any more to produce any significant pressure. Also, boric acid has been added to the seawater. Boric acid is “liquid control rod”. Whatever decay is still going on, the Boron will capture the neutrons and further speed up the cooling down of the core.

The plant came close to a core meltdown. Here is the worst-case scenario that was avoided: If the seawater could not have been used for treatment, the operators would have continued to vent the water steam to avoid pressure buildup. The third containment would then have been completely sealed to allow the core meltdown to happen without releasing radioactive material. After the meltdown, there would have been a waiting period for the intermediate radioactive materials to decay inside the reactor, and all radioactive particles to settle on a surface inside the containment. The cooling system would have been restored eventually, and the molten core cooled to a manageable temperature. The containment would have been cleaned up on the inside. Then a messy job of removing the molten core from the containment would have begun, packing the (now solid again) fuel bit by bit into transportation containers to be shipped to processing plants. Depending on the damage, the block of the plant would then either be repaired or dismantled.

Now, where does that leave us?

* The plant is safe now and will stay safe.
* Japan is looking at an INES Level 4 Accident: Nuclear accident with local consequences. That is bad for the company that owns the plant, but not for anyone else.
* Some radiation was released when the pressure vessel was vented. All radioactive isotopes from the activated steam have gone (decayed). A very small amount of Cesium was released, as well as Iodine. If you were sitting on top of the plants’ chimney when they were venting, you should probably give up smoking to return to your former life expectancy. The Cesium and Iodine isotopes were carried out to the sea and will never be seen again.
* There was some limited damage to the first containment. That means that some amounts of radioactive Cesium and Iodine will also be released into the cooling water, but no Uranium or other nasty stuff (the Uranium oxide does not “dissolve” in the water). There are facilities for treating the cooling water inside the third containment. The radioactive Cesium and Iodine will be removed there and eventually stored as radioactive waste in terminal storage.
* The seawater used as cooling water will be activated to some degree. Because the control rods are fully inserted, the Uranium chain reaction is not happening. That means the “main” nuclear reaction is not happening, thus not contributing to the activation. The intermediate radioactive materials (Cesium and Iodine) are also almost gone at this stage, because the Uranium decay was stopped a long time ago. This further reduces the activation. The bottom line is that there will be some low level of activation of the seawater, which will also be removed by the treatment facilities.
* The seawater will then be replaced over time with the “normal” cooling water
* The reactor core will then be dismantled and transported to a processing facility, just like during a regular fuel change.
* Fuel rods and the entire plant will be checked for potential damage. This will take about 4-5 years.
* The safety systems on all Japanese plants will be upgraded to withstand a 9.0 earthquake and tsunami (or worse)
* I believe the most significant problem will be a prolonged power shortage. About half of Japan’s nuclear reactors will probably have to be inspected, reducing the nation’s power generating capacity by 15%. This will probably be covered by running gas power plants that are usually only used for peak loads to cover some of the base load as well. That will increase your electricity bill, as well as lead to potential power shortages during peak demand, in Japan.

If you want to stay informed, please forget the usual media outlets and consult the following websites:

http://www.world-nuclear-news.org
http://bravenewclimate.com/2011/03/1...ar-earthquake/
http://ansnuclearcafe.org/2011/03/11...ions-in-japan/

[GasoLane]

Originally Posted by cheap

The link below will not go well with the ka-boom, imminent world-is-ending people. If anyone cares to be a little more informed read on:

http://bravenewclimate.com/2011/03/1...e-explanation/

Ya right. The 'Chicken Little Sky is falling' crowd wont like it

Thanks. A good, if long, read.

[GasoLane]

Originally Posted by DAZZLER351

Construction of the Fukushima nuclear power plants

Thank you Dazzler, was that huge post for those of us who don't know how to click a link?

[Road Games]

If we can draw any positive out of this .. I reckon the price of coal is about to skyrocket !!!

While the nuclear power stations stay off line for safety inspections fossil fuels will be needed to keep all those electronic gizmo's working ..

Possibly good times ahead for the mining industry ...

[Road Games]

Originally Posted by GasOLane

Thank you Dazzler, was that huge post for those of us who don't know how to click a link?

A lot of links i have tried to click wont open for me and there is already a virus on Bookface from a vid link .. I do my best to help mate ..

[DJM83]

Thanks Daz, one point i want to raise is this one
* Japan is looking at an INES Level 4 Accident: Nuclear accident with local consequences. That is bad for the company that owns the plant, but not for anyone else.
So it bad for the company as in, their plant is destroyed, employee's hurt or are they going to incur some sort of penalty (Thats how i read it) if is the last one well thats a crock.

[Jim Goose]

http://www.nisa.meti.go.jp/english/index.html

Japans Nuclear and Industrial Safety Agency.
This is the official press release site of the governing body in Japan.

[blueoval]

A 6.0 earthquake has just been reported in nagano. That's the latest from CNN news.

[Keepleft]

Originally Posted by blueoval

A 6.0 earthquake has just been reported in nagano. That's the latest from CNN news.

Been a couple of that range over the last two or so days.

[Jim Goose]

Media is reporting cooling issues at a 3rd reactor now.....

http://www.abc.net.au/news/stories/2...14/3163747.htm

A Japanese nuclear power plant remains in crisis following Friday's massive earthquake and tsunami, with an explosion at a second reactor and cooling functions failing at a third.

The plant's operator, Tokyo Electric Power (TEPCO), says the cooling system at the No. 2 reactor at its Fukushima plant has now failed, Jiji Press reported.

The No. 1 and No. 3 reactors experienced the same problem when their cooling systems were knocked out by the 8.9-magnitude quake and subsequent tsunami which struck a large swathe of the country's coast north of Tokyo.

The failures were followed by explosions in the buildings surrounding those reactors....

[Road Games]

Originally Posted by Jim Goose

Media is reporting cooling issues at a 3rd reactor now.....

http://www.abc.net.au/news/stories/2...14/3163747.htm

Hype ...

[Spudz27]

Originally Posted by DAZZLER351

Construction of the Fukushima nuclear power plants

Was a great read. I have been getting ****y all day at the media being the media and sensationalising every little thing. Then all the people who never bother to read facts ringing the ABC and saying how bad nuclear power is, never get it here, vote greens etc. I texted in and asked those same people if they would like a coffee in the morning, or power bills through the roof to pay for the infastructure to produce the electricity they were talking about. I also made the comment they would be the same whingers and mis informed people who would complain if coal or diesel power were used to create the same sort of needs for countries like Japan.

[g220ba]

There seems to be a real unfounded scare campaign against nuclear power coming from this. It has been said for many years we will never see the likes of Chernobyl ever again, there are so many safety systems in place to prevent such an event. What this situation will do is further improve nuclear power safety systems and emergency techniques.

On the radio earlier i heard one of the stupid greens members sprouting the dangers of nuclear power from this, We need to move on from the scare campaign, deliver the information as needed and start worrying about Japans recovery and the thousands of people who have died and had their lives ruined from the earthquake and tsunami.

[GasoLane]

Originally Posted by DAZZLER351

A lot of links i have tried to click wont open for me and there is already a virus on Bookface from a vid link .. I do my best to help mate ..

Easy fix... Change Browser and NEVER use or trust anything from Facebook unless you have good virus/spyware protection.

[cheap]

It should become obvious that the last thing the engineers, the technicians or nuclear industry wants is a radiation spill.

Engineers go out of their way to provide multiple redundant containment safety features in these reactors. Chernobyl exploded because of flawed operational procedures (human failure) and Chernobyl didn't have a containment building hence the massive radiation leak. All western nuclear reactors have containment buildings and even in the worst possible situation where all cooling fails, the reactor will melt and its contents will be safely contained.

I just wish the media would spin this around into the true story of how excellent the engineering and recovery efforts has been.

• The facility is very old and still withstood an earthquake 7 TIMES more powerful that it was designed
• The facility initiated an automatic shutdown (the instant the earthquake struck) of its reactors and had nearly completed this but then
• The facility lost external power to the station
• The facility switched to battery backup and local generators
• Tsunami wiped out their generators
• Stayed on battery power for as long as their batteries lasted (several hours)
• Trucks arrived with emergency generators, which took time to bring online
• Reactor experienced significant heat, so they vented relatively harmless hydrogen and oxygen gases into the roof of the containment building - this ignited (exploded)
• Pumped copious amounts of cooling seawater around the containment vessel and the reactor is safely cooled

Given all the above, the multiple unexpected failures experienced, the recovery from these situations, given the reactor is now safe and a staggering 9 people have recorded minor radiation levels. Instead of a congratulations, the Australian media continues to report total hype!

[Jim Goose]

Originally Posted by DAZZLER351

Hype ...

Really?? And you know this by?

The other two were also hype im guessing?

http://news.smh.com.au/breaking-news...314-1buo0.html

Japan nuclear fuel rods 'fully exposed'
March 14, 2011 - 11:04PM

AP

A Japanese utility says fuel rods at a troubled nuclear reactor have been fully exposed.

The exposure happened at Unit 2 of the Fukushima Dai-ichi plant - the latest reactor to lose its ability to cool down.

The other two reactors at the plant are facing a meltdown and authorities are racing to cool them with sea water.
Advertisement: Story continues below

Tokyo Electric Power said on Monday sea water is being channelled into Unit 2.

It did not know if the rods were covered yet.

Their exposure raises the risk of the reactor overheating, which can lead to meltdown.

http://edition.cnn.com/2011/WORLD/as...ex.html?hpt=T1

Tokyo (CNN) -- Another reactor at Japan's Fukushima Daiichi nuclear plant lost its cooling capabilities Monday, a government official said.

The problem was detected in the plant's No. 2 reactor Monday afternoon after an explosion rocked the building containing the plant's No. 3 reactor, Chief Cabinet Secretary Yukio Edano told reporters.

"We think that the hydrogen explosion in (the building housing) reactor No. 3 caused the cooling system of reactor No. 2 to stop working," Edano said.

Water levels were falling and pressure was building up inside the No. 2 reactor, he said, and officials were working on a plan to release gas and also inject seawater into that reactor.


Workers have been injecting seawater in a last-ditch effort to cool down fuel rods and prevent a full meltdown at two other reactors at the plant -- No. 1 and No. 3 -- after an 8.9-magnitude earthquake and ensuing tsunami Friday knocked out the reactors' cooling systems.

Japanese officials have said that they are operating under the presumption that there may be a partial meltdown in the No. 3 and No. 1 nuclear reactors. Authorities have not yet been able to confirm a meltdown, because it is too hot inside the affected reactors to check.

There are six reactors at Tokyo Electric Power Company's Fukushima Daiichi plant, located in northeastern Japan about 65 km (40 miles) south of Sendai.

A buildup of hydrogen in the Fukushima Daiichi plant's No. 3 reactor building caused Monday's blast, authorities said, which injured 11 people and sent white smoke billowing above the nuclear plant.

But the explosion did not damage the reactor or result in significant radiation leakage, Edano told reporters.

The explosion blew away the roof and walls of the building housing the reactor, Japan's Kyodo News reported. A similar blast occurred Saturday at the plant's No. 1 reactor.

On Sunday, Edano warned that the same sort of explosion could occur in the No. 3 building.

After Monday's blast, authorities ordered at least 500 residents remaining within 20 kilometers (12 miles) of the plant to stay inside, Edano said. About 200,000 people evacuated the area over the weekend after a government order.

"There is no massive radioactive leakage," Edano said.

Even so, public concern over the possibility remained rampant Monday -- even outside the evacuation zone.

"Everyone is talking about it. There seems to be a real fear about this, an anxiety about it," said CNN's Dr. Sanjay Gupta, reporting from a school serving as an evacuation center about 100 kilometers (62 miles) away from the Fukushima Daiichi plant.


Low levels of radiation were detected at least as far as 100 miles northeast of the plant, according to the U.S. Navy, which repositioned ships and planes after detecting low-level "airborne radioactivity."

The Navy's statement, however, provided some perspective, noting that the maximum potential radiation dose received by any ship personnel when it passed through the area was "less than the radiation exposure received from about one month of exposure to natural background radiation from sources such as rocks, soil, and the sun."

The Tokyo Electric Power Company said in a statement late Sunday that radiation levels outside that plant remained high.

Kyodo, citing the same company, said that there were measurements of 751 microsieverts and 650 microsieverts of radiation early Monday. Both are above the legal limit, albeit less than one reading recorded Sunday.

A microsievert is an internationally recognized unit measuring radiation dosage, with people typically exposed during an entire year to a total of about 1,000 microsieverts.

Authorities early Sunday noted high radiation levels at another plant, located 135 kilometers (85 miles) away in Onagawa. The International Atomic Energy Agency later said that Japanese officials reported that levels had returned to "normal." It also said the increase detected earlier "may have been due to a release of radioactive material from the Fukushima Daiichi nuclear power plant."

Most experts aren't expecting a reprise of the 1986 Chernobyl meltdown, which killed 32 plant workers and firefighters in the former Soviet Union and at least 4,000 others from cancers tied to radioactive material released by the plant.

Analysts said Japan's crisis is unique.

"This is unprecedented," said Stephanie Cooke, the author of "In Mortal Hands: A Cautionary History of the Nuclear Age." "You've never had a situation with multiple reactors at risk."

Japan's 54 nuclear reactors provide about 30% of the country's electricity, according to the World Nuclear Association.


Daiichi's No. 1 reactor -- the oldest of six boiling-water units at the site, according to the nuclear association -- began commercial operation in March 1971. The No. 2 reactor began commercial operation in 1974, and the No. 3 reactor followed two years later.

"Nuclear facilities in Japan ... were built to withstand earthquakes -- but not an 8.9 earthquake," said James Walsh, a CNN contributor and research associate at MIT's security studies program.

The crisis has stoked fears of a full-on nuclear meltdown, a catastrophic failure of the reactor core that has the potential for widespread release of radiation.

Officials are working to prevent such a calamity by injecting seawater and boron into the affected reactors -- even though salt and boron will corrode the reactors, rendering the Daiichi plant inoperable.

"Essentially, they are waving the white flag and saying, 'This plant is done,'" Walsh said. "This is a last-ditch mechanism to try to prevent overheating and to prevent a partial or full meltdown."

The situation -- part of what Prime Minister Naoto Kan called the "toughest and most difficult crisis for Japan" since the end of World War II -- has national and global repercussions as authorities and scientists debate the dangers of nuclear power.

Cooke said that it may take years to fully assess the damage at Japan's worst-hit reactors, much less to get them working again. And authorities may never definitively determine how much radiation was emitted, or how many got sick because of it.

If the effort to cool the nuclear fuel inside the reactor fails completely -- a scenario that experts who have spoken to CNN say is unlikely -- dangerous amounts of radiation could be released into the atmosphere or water. That could lead to widespread cancer and other health problems, experts say.

Authorities have downplayed such a scenario, insisting the situation appears under control and that radiation levels in the air are not dangerous.

The Daiichi plant has a containment vessel, which theoretically would capture radioactive material if a full meltdown occurs.

Edano has said there have been no leaks of radioactive material at any plants. Radioactive steam has been released intentionally to lessen growing pressure in the two Daiichi reactors -- in an amount authorities have described as minimal.

Despite such evidence, Noriyuki Shikata, a spokesman for Japan's prime minister, said Sunday the situation was "under control." His remarks came before Monday's explosion.

Cooke, also editor of Nuclear Intelligence Weekly for the atomic-energy community, said she's not convinced the Japanese are in control.

"The more they say they're in control, the more I sense things may be out of control," she said.

[Road Games]

Originally Posted by Jim Goose

Really?? And you know this by?

The other two were also hype im guessing?

http://news.smh.com.au/breaking-news...314-1buo0.html




http://edition.cnn.com/2011/WORLD/as...ex.html?hpt=T1

YEP !

[Road Games]

Originally Posted by cheap

Given all the above, the multiple unexpected failures experienced, the recovery from these situations, given the reactor is now safe and a staggering 9 people have recorded minor radiation levels. Instead of a congratulations, the Australian media continues to report total hype!

Qouted for reality purposes...

[cheap]

Originally Posted by Jim Goose

Really?? And you know this by?

The other two were also hype im guessing?

http://news.smh.com.au/breaking-news...314-1buo0.html




http://edition.cnn.com/2011/WORLD/as...ex.html?hpt=T1

Jim, both SMH and CNN are left leaning "rags". SMH is commonly known as Soviet Morning Herald and CNN founded by Ted Turner who has devoted his considerable assets to environmental causes (i.e Greeny)

You provided the link to Japan's Nuclear and Industrial Safety Agency (NISA), have you bothered to read NISA statements and compared these to sensationalist rants from the Soviet Morning Herald or CNN?

You seem to be keen on hyping this up, why? Do you work for Fairfax?