Japan Earthquake News

[rpm]

They will not make forms to hold the concrete. They will just keep pumping boron laced concrete on top of boron laced concrete in progressively thicker slurry and make a giant mound over the reactors. It will not resemble a building. It will look like a giant blob of concrete. After that is completed and the area decontaminated they may go back and cover that with something that resembles a building.

The squadron of giant concrete pumps being sent to Fukushima will be able to reach all the way down to the bottom of the reactors and pinpoint where the concrete goes.

[Sundowner]

Wow...I don't think this has ever been attempted on a melting BWR.(Let alone 2 or three)
The book just keeps getting written as we go along.
Force out the hydrogen buildups with inert gas.

Perhaps some added boron would be helpful to reduce free neutron propagation.

Hope it helps...another hydrogen explosion especially from any already breached primary containment vessel(s) would be devastating...
From other news reports, I gather this procedure will be attempted at the other two(2) crippled units.  

Regards,
Sun

Nitrogen Injected at Crippled Japan Nuke Plant to Prevent Explosion

The Tokyo Electric Power Co. injected nitrogen into a reactor Thursday at the crippled Fukushima Dai-ichi nuclear plant to prevent an explosion, Kyodo News reports.

Nitrogen was injected into the Unit 1 reactor, a process that could take several days, the Japanese news agency reports.

The inert gas can prevent highly combustible hydrogen from exploding. There have already been three explosions at the compound in the early days of the crisis that was set in motion March 11 when the reactors' cooling systems were crippled by Japan's 9.0-magnitude earthquake and tsunami.

Nitrogen normally is present inside the containment that surrounds the reactor core. Technicians will start pumping more in as early as Wednesday evening, said Junichi Matsumoto, a spokesman for the plant operator. They will start with Unit 1, where pressure and temperatures are highest.

"The nitrogen injection is being considered a precaution," said spokesman Hidehiko Nishiyama of Japan's Nuclear and Industrial Safety Agency. Nishiyama also denied reports that there was "immediate danger" of an explosion.

This comes as workers stopped a highly radioactive leak into the Pacific off Japan's flooded nuclear complex Wednesday......

http://www.foxnews.com/world/2011/04/06/radiation-level-japan-seawater-millions-times-legal-limit/?test=latestnews

[Sundowner]

These plants are now completely unapproachable by humans.
Only non-biologicals can approach.

Not good.

Regards,
Sun

Unmanned plane to be used to check radiation levels

TOKYO, April 7, Kyodo

The government intends to use a small U.S. unmanned plane to check radiation levels around spent nuclear fuel pools at the crippled Fukushima Daiichi nuclear power plant, government sources said Wednesday.

The adoption of the remote-controlled T-Hawk aircraft, which is capable of hovering and moving vertically, was proposed by the U.S. government which has been using it for reconnaissance purposes in military operations in Iraq and other countries, the sources said.

Pools housing spent nuclear fuel rods are open and Tokyo Electric Power Co., the operator of the Fukushima plant, has been pouring massive amounts of water into them to cool them down.

As water contaminated with radioactive materials could flow out of the pools, machines to cool them with recycled water need to be reactivated as soon as possible. But workers are unable to approach them as surrounding radiation levels are believed to be extremely high.

In addition, radioactive substances could fly apart if the rods are exposed as water levels drop in the pools.

With the U.S. side especially concerned about such a risk at the No. 4 reactor, the aircraft is expected to be first used to examine radiation levels around it, the sources said.

Goshi Hosono, a special adviser on the Fukushima crisis to Prime Minister Naoto Kan, said that as there are more than 10,000 spent nuclear fuel rods, it will take ''considerable time'' to process them....

http://english.kyodonews.jp/news/2011/04/83630.html

[Sundowner]

http://www.nytimes.com/2011/04/06/world/asia/06nuclear.html?_r=4&hp=&pagewanted=all

U.S. Sees Array of New Threats at Japan’s Nuclear Plant
By JAMES GLANZ and WILLIAM J. BROAD
Published: April 5, 2011

United States government engineers sent to help with the crisis in Japan are warning that the troubled nuclear plant there is facing a wide array of fresh threats that could persist indefinitely, and that in some cases are expected to increase as a result of the very measures being taken to keep the plant stable, according to a confidential assessment prepared by the Nuclear Regulatory Commission.

Among the new threats that were cited in the assessment, dated March 26, are the mounting stresses placed on the containment structures as they fill with radioactive cooling water, making them more vulnerable to rupture in one of the aftershocks rattling the site after the earthquake and tsunami of March 11. The document also cites the possibility of explosions inside the containment structures due to the release of hydrogen and oxygen from seawater pumped into the reactors, and offers new details on how semimolten fuel rods and salt buildup are impeding the flow of fresh water meant to cool the nuclear cores.

In recent days, workers have grappled with several side effects of the emergency measures taken to keep nuclear fuel at the plant from overheating, including leaks of radioactive water at the site and radiation burns to workers who step into the water. The assessment, as well as interviews with officials familiar with it, points to a new panoply of complex challenges that water creates for the safety of workers and the recovery and long-term stability of the reactors.

While the assessment does not speculate on the likelihood of new explosions or damage from an aftershock, either could lead to a breach of the containment structures in one or more of the crippled reactors, the last barriers that prevent a much more serious release of radiation from the nuclear core. If the fuel continues to heat and melt because of ineffective cooling, some nuclear experts say, that could also leave a radioactive mass that could stay molten for an extended period.

The document, which was obtained by The New York Times, provides a more detailed technical assessment than Japanese officials have provided of the conundrum facing the Japanese as they struggle to prevent more fuel from melting at the Fukushima Daiichi plant. But it appears to rely largely on data shared with American experts by the Japanese.

Among other problems, the document raises new questions about whether pouring water on nuclear fuel in the absence of functioning cooling systems can be sustained indefinitely. Experts have said the Japanese need to continue to keep the fuel cool for many months until the plant can be stabilized, but there is growing awareness that the risks of pumping water on the fuel present a whole new category of challenges that the nuclear industry is only beginning to comprehend.

The document also suggests that fragments or particles of nuclear fuel from spent fuel pools above the reactors were blown “up to one mile from the units,” and that pieces of highly radioactive material fell between two units and had to be “bulldozed over,” presumably to protect workers at the site. The ejection of nuclear material, which may have occurred during one of the earlier hydrogen explosions, may indicate more extensive damage to the extremely radioactive pools than previously disclosed........

[Bodhi]

It is still all speculation.  No one except those who are there and intimately involved are going to be in the know. 

[icepac]

The agencies reporing need to make the distinction between "pressure vessel", "containment vessel", and reactor building when using the word "breach".

[MarineUS]

well a 7.4 hit them again and they now have ANOTHER tsunami warning..... jeeeeez

http://www.break.com/index/strange-object-washed-up-on-japans-shore-2039431  - wth is that? O_o

[Ripsnort]

Just announced: To date, 10,000 + Boeing employees have donated $1,000,000 to the Japan relief fund through payroll deduction.

We rock!   

[EskimoJoe]

Just announced: To date, 10,000 + Boeing employees have donated $1,000,000 to the Japan relief fund through payroll deduction.

We rock!   

Voluntary I hope?

[mbailey]

Voluntary I hope?

Lots of Corporations will send out some type of notification asking if you want a portion of your paycheck to go to something like this. My company does it all the time. Its all on a voluntary basis.

Wtg Boeing workers  

[EskimoJoe]

Lots of Corporations will send out some type of notification asking if you want a portion of your paycheck to go to something like this. My company does it all the time. Its all on a voluntary basis.

Wtg Boeing workers  

That makes everything all the sweeter, wtfg Boeing!

[68ZooM]

well a 7.4 hit them again and they now have ANOTHER tsunami warning..... jeeeeez

http://www.break.com/index/strange-object-washed-up-on-japans-shore-2039431  - wth is that? O_o

Godzilla Egg

[Megalodon]

State of stricken Fukushima Dai-ichi nuclear reactors as of today per Tepco so about 3 x worse.

Reactor No. 1
Overheating has caused a partial meltdown of the reactor core. TEPCO believes some 70 percent of the reactor’s 400 fuel rods have been damaged.

Workers have injected pure water, switching from sea water used last month, into the pressure vessel via a pump, but the cooling system has not been restored yet.

With hydrogen and oxygen likely to have accumulated inside the reactor vessel, workers began pumping inert nitrogen gas early Thursday to prevent a possible hydrogen blast.

Workers had begun pumping out radioactive water from the basement of the adjacent turbine building, but they found more in a trench outside the turbine building, about 56 meters from the ocean.


Reactor No. 2
The reactor is also believed to have suffered a partial meltdown, with about 30 percent of 548 fuel rods likely damaged.

The torus—the reactor’s suppression pool which controls the pressure inside the reactor container—has likely been damaged.

Spent fuel rods in the pool were fully exposed at one stage, but TEPCO has said the rods are now submerged in water and in a stable condition.

A puddle of highly contaminated water was found in the basement of the turbine building and outside in a trench, where a radiation reading of over 1,000 millisieverts per hour was measured.

Workers have injected pure water containing boric acid into the pressure vessel, after dumping sea water as an emergency means.

They found a crack in a seaside concrete pit near this reactor, which was leaking highly radioactive water.

After several failed attempts to seal the crack, using cement, and even newspapers and sawdust, workers stopped the leak on Wednesday morning after injecting sodium silicate, a chemical agent known as “water glass,” to solidify soil near the pit.


Reactor No. 3
A hydrogen explosion badly damaged this reactor’s outer building, and a partial meltdown is also suspected. TEPCO said about 25 percent of the reactor’s 548 fuel rods may be damaged.

Three workers were exposed to high levels of radiation last month when they stepped in contaminated water at the basement of the turbine building. They were found to have suffered no major injury.

Workers had used sea water to cool both the reactor and spent fuel pool, but they have now changed to fresh water.


Reactor No. 4

This reactor was undergoing maintenance when the quake struck. There were no rods in the reactor core.

Fires broke out in the building several days after the quake. The fires were put out with water, which made its way into the spent fuel pool.

Firefighters doused the spent fuel pool using a concrete pumping vehicle, usually used in the construction industry. TEPCO has said the reactor’s spent fuel pool is now submerged in water.

Contaminated water was found in the basement of the turbine building, but workers have yet to remove it.

Reactor Nos. 5 and 6

The two reactors were undergoing maintenance when the quake hit, but their fuel rods were already placed in the cores as they were prepared for operation.

Workers have created three holes in each of the two reactor buildings, aiming to vent hydrogen out and prevent an explosion.

They have restarted the cooling systems of the two reactors and the spent fuel pools, which have remained stable.


Reactor Nos. 5 and 6

The two reactors were undergoing maintenance when the quake hit, but their fuel rods were already placed in the cores as they were prepared for operation.

Workers have created three holes in each of the two reactor buildings, aiming to vent hydrogen out and prevent an explosion.

They have restarted the cooling systems of the two reactors and the spent fuel pools, which have remained stable.


Months or possible years to bury it all.

[Sundowner]

Here's a snip from Thursday's quake report....
Sun


SENDAI, Japan –  SENDAI, Japan -- A strong aftershock ripped through northeastern Japan, killing two people, knocking out power to vast areas Friday and piling misery on a region still buried under the rubble of last month's devastating tsunami.

The 7.1-magnitude tremor late Thursday was the strongest since northeastern Japan's jumbo 9.0-magnitude quake March 11. The latest shattered windows, kicked items from shelves and collapsed some roofs that weren't already demolished, but generated no tsunami and largely spared the region's nuclear plants. Some slightly radioactive water spilled at one plant, but the tsunami-crippled Fukushima Dai-ichi complex reported no new problems.

Matsuko Ito, who has been living in a shelter in the small northeastern city of Natori since the tsunami, said there's no getting used to the terror of being awoken by shaking. She said she started screaming when the quake struck around 11:30 p.m.

"It's enough," the 64-year-old while smoking a cigarette outside. "Something has changed. The world feels strange now. Even the way the clouds move isn't right."

Many people have lived without water and electricity for nearly a month, and the latest tremor sunk more homes into blackness: About 2.6 million households -- about 40 percent of those supplied in the area -- were dark Friday, said Souta Nozu, a spokesman for Tohoku Electric Power Co., which serves northern Japan.
Six conventional plants in the area were knocked out, though three have since come back online and the others should be up again within hours, Nozu said. But with power lines throughout the area damaged, it was not clear whether normal operations would be restored, he said.

Several nuclear power plants briefly switched to diesel generators but were reconnected to the grid by Friday afternoon. One plant north of Sendai -- which has been closed since the tsunami -- briefly lost the ability to cool its spent fuel pools, but quickly got it back.

At a plant in Onagawa, some radioactive water splashed out of the pools but did not leave a containment building, Tohoku Electric said. Such splash-out is "not unusual, although it is preferable that it doesn't happen," according to Japanese nuclear safety agency official Tomoho Yamada.

"Closer inspection could find more problems," said agency spokesman Hidehiko Nishiyama, but no radiation was released into the environment at Onagawa.

The plant began leaking oil into the ocean in the first earthquake, and the flow escaped a containment boom in Thursday's tremor, according to coast guard spokesman Hideaki Takase. By Friday, the leak had been contained again, he said.............

http://www.foxnews.com/world/2011/04/07/tsunami-alert-issued-large-quake-strikes-northeastern-japans-coast/?test=latestnews

[Megalodon]

They will not make forms to hold the concrete. They will just keep pumping boron laced concrete on top of boron laced concrete in progressively thicker slurry and make a giant mound over the reactors. It will not resemble a building. It will look like a giant blob of concrete. After that is completed and the area decontaminated they may go back and cover that with something that resembles a building.
 

 I don't think they will able to do that as the reactor buildings are so close to the water. In #2 they will use the building as the form and poor 6" to 1' increments. They will have to make some kind of containment for the cement around the others.