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Meltdown Likely Under Way At Japan Nuclear Reactor


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Here's a decent image of the reactor buildings and what happened to them:

japan-reactor2.jpg

Clearly visible is the different construction (steel frame + cladding) of the top part. Cladding blew off when the hydrogen exploded, steel structure and rest of the building at #1 seems still intact.

Edited by Jdietz
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Kyodo News:

Fuel rods at No. 2 reactor fully exposed for about 2.5 hours [late this afternoon]: agency

NHK:

TEPCO is considering opening a hole in the reactor housing building to release hydrogen generated by the exposed fuel rods.

Might be a wise move, why have another big explosion you know will be coming. Venting the pressure before it gets too much will cause less damage to surrounding parts of the system.

Conversely it may cause the very thing they're trying to avoid. I thought this should have been done a long time ago, in fact was shocked to hear it's not a built in redundant safety feature. I'd not want to be the one drilling holes in it now however with it filled with hydrogen already, may end up being the first meltdown related casualties (as in deaths) in this calamity....

Edited by WarpSpeed
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Well, I for one wouldn't volunteer to drill a hole in that particular wall, with a potential mixture of hydrogen and oxygen on the other side of it, and on top of a poorly cooled reactor vessel with fuel rods exposed....

In the words of Harry Enfield; "now I don't believe you wanted to be doing that....."

Yes, my sentiments exactly...

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Kyodo News:

Radiation twice the maximum seen so far detected at nuke plant Monday: TEPCO

Fuel rods fully exposed again as of 11 p.m.

00:42 15 March 2011 JST

Edited by jfchandler
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Kyodo News:

Radiation twice the maximum seen so far detected at nuke plant Monday: TEPCO

Fuel rods fully exposed again as of 11 p.m.

00:42 15 March 2011 JST

Isn't this a big problem? Fully exposed rods? I keep watching for a post from you guys.....

Isn't 11pm very recent? The posting times confuse me.

Edited by Lopburi99
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Kyodo News is reporting that damage from Monday's explosion at Daiichi Reactor No. 3 may have directly led to tonight's problems with Reactor No. 2.

The seawater injection operation started at 4:34 p.m., but water levels in the No. 2 reactor have since fallen sharply with only one out of five fire pumps working. The other four were feared to have been damaged by a blast that occurred in the morning at the nearby No. 3 reactor.

The utility firm said a hydrogen explosion at the nearby No. 3 reactor that occurred Monday morning may have caused a glitch in the cooling system of the No. 2 reactor.

AND

With only one fire pump working, TEPCO is placing priority on injecting water into the No. 2 reactor, although both the No. 1 and No. 3 reactors still need coolant water injections, according to the agency.

AND

An update on the day's injuries from the Reactor No. 3 explosion

TEPCO said seven workers at the site and four members of the Self-Defense Forces were injured. Of the 11, two were found to have been exposed to radiation and are receiving treatment.

Edited by jfchandler
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Yes, all this is very recent. The times below are Japanese time...

So 11 pm Japan time meant 9 pm Thai time..

I'll try to be more clear on that, but unless otherwise noted, assume the times in these reports are Japan time.

Kyodo News:

Radiation twice the maximum seen so far detected at nuke plant Monday: TEPCO

Fuel rods fully exposed again as of 11 p.m.

00:42 15 March 2011 JST

Isn't this a big problem? Fully exposed rods? I keep watching for a post from you guys.....

Isn't 11pm very recent? The posting times confuse me.

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French nuclear agency rates Japan accident 5 or 6

Reuters - 03/14/2011

PARIS - France's ASN nuclear safety authority said on Monday the nuclear accident in Japan could be classed as level 5 or 6 on the international scale of 1 to 7, on a par with the 1979 US Three Mile Island meltdown.

The estimate of the severity of the accident at Tokyo Electric Power Co's Fukushima Daiichi plant, based on the ASN's assessment of data provided by Japan, is above the rating of four given by Japan's nuclear safety agency.

"Level four is a serious level," ASN President Andre-Claude Lacoste told a news conference, but added: "We feel that we are at least at level five or even at level 6."

Edited by jfchandler
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Japan has asked IAEA for expert help: UN watchdog

Agence France-Presse -- March 14

Japan has officially asked the UN atomic watchdog to send a team of experts to help in the current nuclear crisis, International Atomic Energy Agency chief Yukiya Amano said Monday.

"Today, the government of Japan asked the agency to provide expert missions. We are in discussions with Japan on the details," Amano told IAEA member states in a closed-door technical briefing at the watchdog's Vienna headquarters.

Immediately after the devastating earthquake hit Japan on Friday, damaging the Fukushima nuclear plant located 250 kilometres northeast of Tokyo, the IAEA made a formal offer of assistance to the government.

Edited by jfchandler
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ABC News reporting Reactor No. 3 has a "leak"

Japan's Nuclear Emergency: Third Fukushima Reactor Failing

After Two Explosions at Plant, Third Reactor's Fuel Rods Exposed

ABC News

By DAVID MUIR and JESSICA HOPPER

March 14, 2011

A series of nuclear reactors continue to deteriorate in the wake of Japan's devastating earthquake and tsunami, raising worries of a nuclear meltdown.

After two hydrogen explosions in three days at the Fukushima Daiichi plant, a third reactor has lost its ability to cool. Officials are increasingly concerned about unit 2 at the plant.

"They continue to work hard to raise the water level to cover the fuel. Let's pray again," Tatsujiro Suzuki, vice chairman of Japan's Atomic

Energy Commission, posted on Facebook today.

The fuel rods on unit 2 have been fully exposed for the second time today, a dangerous development in the effort to stop the reactor from

melting down.

The exposure of the fuel rods means that the temperature in the reactor is likely to rise, which will allow it to make steam. The steam could

lead to the creation of hydrogen and cause another explosion, experts said.

Knowing how long the fuel rods have been exposed is key to understanding if there is a real chance of a meltdown, said Dr. Peter Hosemann, a nuclear energy expert and professor at the University of California at

Berkeley.

"Having too much of the fuel rods exposed for too long of a time can lead to the core melt. Again, if a core melt happens, the reactor

pressure vessel and the containment are designed to contain it," Hosemann said.

Japanese officials acknowledged that the fuel rods appear to be melting inside all three of the reactors at the Fukashima plant.

"Although we cannot directly check it, it's highly likely happening," Chief Cabinet Secretary Yukio Edano told the Associated Press.

Officials first became concerned about unit 2 at the plant after pressure began rising in the reactor. They began pouring sea water onto

the reactor Monday morning.

Workers had to stop pouring the sea water when they discovered that the reactor was also losing fuel, meaning that the fuel rods were exposed,

NHK News reported.

Workers had returned to pumping sea water when the fuel rods were exposed for a second time.

While unit 1, the first reactor to explode at the plant, appears to be stable, unit 3, which exploded early Monday morning in Japan, reportedly has a leak in its bottom.

"We've never encountered this type of situation in history before," said Joe Cirincione, a nuclear policy expert. "We are beyond a reactor

crisis at this point. This is a nuclear system crisis. The entire northern part of the Japanese nuclear power system has been delivered a

body blow."

The leak at unit 3 is making it difficult to keep the core of the reactor covered with sea water, Dr. Michio Kaku, a physicist, said.

"The situation is getting worse by the hour. We haven't hit bottom yet... We now have reports that unit 3 suffered perhaps a 90 percent

uncovering of the core -- this is unprecedented since Chernobyl," Kaku said.

Japanese officials insist that things are under control at the nuclear plant and that radiation levels are safe.

"They haven't stabilized the sea water yet. Remember, they're hanging in there right there with the fingernails. This is how close we are to a full-scale meltdown. So it's stable in the sense that you're stable when you're hanging by your fingernails," Kaku said.

MORE: http://abcnews.go.co...13131123&page=2

Edited by jfchandler
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Japanese Officials: Nuclear Fuel Rods Melting in 3 Reactors

Outlook grim following two explosions

By Katy O'Donnell

Monday - March 14 2011 12:18 p.m. NATIONALJOURNAL.COM

Japanese officials confirmed Monday that nuclear fuel rods appear to be melting inside three reactors compromised by Friday’s earthquake, though nuclear experts differ on whether the outer chamber of a reactor melting in fact constitutes a partial “meltdown.”

http://www.nationaljournal.com/energy/japanese-officials-nuclear-fuel-rods-melting-in-3-reactors-20110314

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