Jump to content

Meltdown Likely Under Way At Japan Nuclear Reactor


george

Recommended Posts

BREAKING NEWS:

Meltdown Likely Under Way At Japan Nuclear Reactor

TOKYO (AP) — Japan's top government spokesman says a partial meltdown is likely under way at second reactor affected by Friday's massive earthquake.

Chief Cabinet Secretary Yukio Edano said Sunday that radiation at the nuclear power plant in Fukushima briefly rose above legal limits, but it has since declined significantly.

Three reactors at the plant lost their cooling functions in the aftermath of quake and tsunami because of a power outage.

Some 170,000 people have been ordered to evacuate the area within 12 miles (20 kilometers) of the plant.

The plant is 170 miles (270 kilometers) north of Tokyo.

-- AP 2011-03-13

Link to comment
Share on other sites

  • Replies 3.3k
  • Created
  • Last Reply

Top Posters In This Topic

Wind direction monitored near quake-hit Japan nuclear plant

TOKYO | Sat Mar 12, 2011 10:37pm EST

(Reuters) - The wind over a Japanese nuclear plant that is leaking radiation will continue blowing from the south, which could affect residents north of the facility, an official at Japan's Meteorological Agency said on Sunday.

The Fukushima Daiichi plant, operated by Tokyo Electric Power Co's, is located about 240 km (150 miles) north of Tokyo on the country's northeast coast.

The wind will keep blowing from the south in the area from noon until early evening, the official said.

The direction of the wind is a key factor in judging possible damage to the environment from the radiation leaking from the plant, which was devastated on Friday by Japan's biggest earthquake on record and a subsequent tsunami.

The Japan Meteorological Agency said on its website that the weather in the area is likely to be clear on Sunday, with the maximum temperature of 15 Celsius (60 F).

The plant was damaged by Friday's 8.9 magnitude quake, which sent a 10-meter (33-foot) tsunami ripping through towns and cities across the northeast coast.

Tokyo Electric Power Co (TEPCO) said earlier on Sunday that radiation levels have risen above the safety limit around its nuclear plant and the company has informed the government of an "emergency situation", Kyodo agency reported.

It did not pose an immediate threat to human health, the company said.

-- Reuters 2011-03-13

Link to comment
Share on other sites

Japan Tries Using Seawater to Cool Damaged Reactor

By YUKA HAYASHI And ANDREW MONAHAN

TOKYO—Japanese officials continued their battle to control dangerous reactor overheating in the nation's worst nuclear accident that followed Friday's earthquake, as they resorted to an unprecedented attempt to cool the reactor with seawater.

http://online.wsj.com/article/SB10001424052748703555404576195700301455480.html

Link to comment
Share on other sites

This has been mentioned in the other thread (now reserved for general EQ stuff) But it deserves mention here too... the Fukushima plant was built and designed to withstand up to a 7.9 mag quake, not the 8.9 (or whatever number they finally settle on) that actually occurred.

Excerpted from the above WSJ link article..

Separately, company documents show that Tokyo Electric tested the Fukushima plant to withstand a maximum seismic jolt lower than Friday's 8.9 earthquake. Tepco's last safety test of nuclear power plant Number 1—one that is currently in danger of meltdown—was done at a seismic magnitude the company considered the highest possible, but in fact turned out to be lower than Friday's quake. The information comes from the company's "Fukushima No. 1 and No. 2 Updated Safety Measures" documents written in Japanese in 2010 and 2009. The documents were reviewed by Dow Jones.

The company said in the documents that 7.9 was the highest magnitude for which they tested the safety for their No. 1 and No. 2 nuclear power plants in Fukushima

Edited by jfchandler
Link to comment
Share on other sites

Tywais wrote:

micro-Sievert or 1 millionth of a Sievert. I work in nuclear physics for about 40 years but being American normally use REM, mRem and uRem so have to think a bit about the relationship between the two units. You know, like kg/lbs meters/feet. smile.gif

Ahhh... as a fellow American, that would explain it... Yeesh.. another lbs/kg thing???

Rem I know/knew... mSv not... So they're not the same unit of measurement...totally different levels?

Link to comment
Share on other sites

Quote: Three reactors at the plant lost their cooling functions in the aftermath of quake and tsunami because of a power outage.

Oh the irony; reactors overheating because of power failure.

Isn't that what they do; generate electricity?

Actually I hope they don't melt down and everybody is safe; they have been through enough this week!

Link to comment
Share on other sites

Did we post on this already...from NHK

Japan quake magnitude raised to 9.0

Japan's Meteorological Agency says the magnitude of Friday's earthquake that hit the Pacific coast of northeastern Japan was 9.0 instead of 8.8 as earlier announced.

The agency made the correction on Sunday morning after analyzing seismic waves and other data. The magnitude is equivalent to that of the 2004 earthquake off Sumatra, Indonesia, which triggered massive tsunamis in the Indian Ocean.

The agency says the focal zone of Friday's quake was about 500-kilometers long and 200-kilometers wide. Destructive movement along the fault continued for more than 5 minutes.

The Meteorological Agency says only 4 other quakes in the world have recorded magnitudes of 9 or over.

The largest was the magnitude 9.5 quake that hit the Chilean coast in 1960, killing more than 1,600. The quake also triggered tsunamis in Japan, leaving 142 people dead.

The 2004 quake off Sumatra registered a magnitude of 9.1. Subsequent giant tsunamis killed more than 200,000 people.

Sunday, March 13, 2011 12:40 +0900 (JST)

http://www3.nhk.or.j...lish/13_21.html

Edited by jfchandler
Link to comment
Share on other sites

Reply to post in other thread:

Thanks, I understand this point of view, but cooling it with sea-water would have the same effect as boric acid. - The reactor would never be up again. This is talked about since more than 12 hours.

The problems seem to be with the injection of sea-water and boric acid.

Although Boric acid isn't a standard regulating compound in a BWR, it is just an additive to the coolant, and does no harm to the reactor. It regulates the reaction in much the same way as the control rods do. When flushed out again, reaction starts back up.

Sea water however is messily corrosive crap, will clog up pipes and destroy pumps and seals etc.

The main problem seems to be that without power, there is not enough water pressure to overcome the reactors pressure, so you don't get any water in. This causes the water inside the reactor to boil off, increasing the pressure even more.

Releasing this pressure means releasing lightly radioactive water to the atmosphere (and maybe causing another explosion just like in #1, as hydrogen may have formed).

So basically what they will be doing is choosing between evils, carefully weighing:

- Scrapping the reactor / Trying to salvage it

- Venting radioactive steam / keep trying to keep enough water in the reactor

- Explosion risks / Radiation risks

Link to comment
Share on other sites

More from NHK quoting the Chief Cabinet Secretary on the evacuation...

On the evacuation of residents around the No.1 plant, Edano said 114 people are still within 10 kilometers of the power station. He said that 180,000 residents of areas between 10 and 20 kilometers away started to evacuate early on Sunday morning.

As for the No.2 plant, the top government spokesman said people living within 3 kilometers have evacuated the zone, and more than 30,000 who are within 10 kilometers began evacuation early on Sunday morning.

I

Link to comment
Share on other sites

Why does the densest seismic network in the world/such an earthquake prone area have Nuclear Reactors.

Of course they need the power it supplies...but still it makes one wonder.

unlimited human insanity mixed with greed and power-games is the most likely answer.

Link to comment
Share on other sites

Someone yesterday posted a graphic of the actual international scale, in visual pyramid form, in the other general EQ thread....

Nuclear accident rated at level 4

The Japanese government rates the accident at the Fukushima Number One nuclear power plant at level 4 on an international scale of 0 to 7.

Two radioactive substances, cesium and radioactive iodine, were detected near the Number One reactor at the plant on Saturday. Their presence indicates nuclear fission of uranium.

The Nuclear and Industrial Safety Agency said that fuel in the reactor partially melted. It's the first such accident in Japan.

A level 4 on the International Nuclear and Radiologocal Event Scale includes damage to fuel and release of significant quantities of radioactive material within an installation.

It's the same level as a criticality accident at a nuclear fuel processing plant in Tokai Village in Ibaraki Prefecture, south of Fukushima, in 1999.

The agency called the accident very regrettable even though it was triggered by an earthquake.

Sunday, March 13, 2011 07:08 +0900 (JST)

http://www3.nhk.or.j...lish/13_06.html

Edited by jfchandler
Link to comment
Share on other sites

where is the radiation going? Is it blowing towards North America?

My question then is, will it be safe to fly? If one looks at the air routes, they seem to fly over Japan and through the radiation cloud.

Please, someone tell me I am wrong.

The general wind direction from the leaking plant at present is blowing to the north... away from Tokyo and more urban areas.

Since we don't exactly know what levels of radiation are making it into the environment or how they'll be dispersed, kind of hard to say.

Link to comment
Share on other sites

Why does the densest seismic network in the world/such an earthquake prone area have Nuclear Reactors.

Of course they need the power it supplies...but still it makes one wonder.

unlimited human insanity mixed with greed and power-games is the most likely answer.

Sad but likely true

Link to comment
Share on other sites

where is the radiation going? Is it blowing towards North America?

My question then is, will it be safe to fly? If one looks at the air routes, they seem to fly over Japan and through the radiation cloud.

Please, someone tell me I am wrong.

You're wrong :)

Relax. At this time the only thing released is steam, which is slightly radioactive because it has been through the reactor. The amounts measured at the site itself poses no immediate danger, let alone when flying at 10KM (30,000 feet) over it. It would surprise me if it was even measurable at that level.

So no 'radiation cloud' or anything at the moment, all the reactor cores seem to be intact still at the moment of this writing.

Link to comment
Share on other sites

LB, so if I'm following this correctly, they are now either releasing steam, or preparing to, at all 3 of the reactors that had been running at the Fukushima Daichi plant.... 1-3 there were in operation at the time of the quake. reactors 4-6 were down for scheduled maintenance.

And generally speaking, it seems, we should assume that steam is containing some levels of radioactivity... the exact level and nature probably depending on which reactor is involved... the one like No. 1 that has had a partial meltdown probably greater...

Link to comment
Share on other sites

where is the radiation going? Is it blowing towards North America?

My question then is, will it be safe to fly? If one looks at the air routes, they seem to fly over Japan and through the radiation cloud.

Please, someone tell me I am wrong.

WIND

CNN just had a professor on who explained that there is no melt dow... reactors are build failure-proof... the radiation from a scan are 100-1,000 times more than standing next to the reactor for an hour...

In other words: Carry on, don't worry be happy. Nothing to see here folks, move along.

Link to comment
Share on other sites

Guest
This topic is now closed to further replies.
  • Recently Browsing   0 members

    • No registered users viewing this page.





×
×
  • Create New...