Nuclear emergency declared at quake-damaged reactor

[googlegoogle]

http://www.usatoday.com/news/world/2...reactors_N.htm

[WoodDraw]

Originally Posted by DJ's left nut

Then isn't this all delaying the inevitable?

If that cooling system is ****ed and the mechanics of simply building a new one seem prohibitive, it's not like they're going to be able to keep a bucket brigade running for the next 4 years.

How can this have any other possible conclusion but a melt-down?

It's really a matter of days. If they can keep water flowing for a few more days, the risk will fall rapidly. For better or worse, this will all be over within a week.

[Rams Fan]

Something random I found out today:

3/10/11(Day the Earthquake/Tsunami happened in Japan)
+ 9/11/01
_____________________________________
12/21/12

Originally Posted by Amnorix

CNN Blog confirming fire at Reactor 4

[6 p.m. ET Tuesday, 5 a.m. Wednesday in Tokyo] Fire has been discovered in the northeastern corner of the building of reactor No. 4 at the Fukushima Daiichi nuclear plant in northeastern Japan, the power company says.

Fire has been discovered.... strange way of putting that, I think.

[Donger]

Originally Posted by BucEyedPea

Do you work in nuclear power? If so, as an engineer?

No.

[Discuss Thrower]

Originally Posted by Rams Fan

Something random I found out today:

3/10/11(Day the Earthquake/Tsunami happened in Japan)
+ 9/11/01
_____________________________________
12/21/12 /teetubya

FYP

[DJ's left nut]

Originally Posted by Donger

No.

If the reactors SCRAMed successfully and the fission was stopped, the decay heat generated rather quickly decreases. But, unless you have water constantly surrounding the core AND being circulated AND being replaced with cool water, there is no where for the heat to go.

Right, but doesn't that get back to the crux of it?

If the cooling system is fried and nobody seems capable of keeping this water running, what's the end game? They're not going to be able to keep that water constantly surrounding the core, etc, etc...

This seems to be a losing battle they're waging here.

I think that now would be the perfect time to take over Japan if one were so inclined. Do they have anything we want - like besides their nuclear power capabilities?

[DJ's left nut]

Originally Posted by WoodDraw

It's really a matter of days. If they can keep water flowing for a few more days, the risk will fall rapidly. For better or worse, this will all be over within a week.

Fair enough.

The impression I was getting was that even in a few days/weeks, these were all still going to be putting off enough heat to make this entire affair impossible to contain.

[Rams Fan]

I know this has probably been said before, but this helped me have a better understanding about why and how the nuclear reactors failed to cool down:

After the earthquake hit, the first safety system to prevent a melt-down was activated. Control rods rose into the nuclear reactor to stop the nuclear fission— but the fuel rods were still hot. Because of the power outage that occurred after the earthquake, water was not circulated to cool down the rods.

The second safety system turned on, and the generator began spraying the rods with coolant. An hour later, that emergency generator stopped— possibly because the tsunami hit the country at that time.

The third safety system then turned on. This system converts steam traveling through the pipes into water. But the water level dropped, and temperatures continued to rise.

All thee safety measures failed.

A professor from Japan's Atomic Energy Commission, whom was involved in the construction of the Fukushima plants, said he thinks the cooling water somehow leaked from the reactor.

“The reactor's coolants must have leaked somewhere in the building,” he said Tuesday. “We thought we had taken adequate precautions for a tsunami, but what happened was beyond our expectations.”

The Japanese government warned 140,000 people to stay within their homes on Tuesday, and an estimated 70,000 people have been evacuated from a 12-mile area around the nuclear plant.

http://www.ktsm.com/news/breakdown-h...d-to-cool-down

[Donger]

Originally Posted by Amnorix

I wish I had a better idea of what the temperature of the spent fuel was in the reactors and the pool.

0.2% of what I understood the operating reactor temperature to be would not be a significant number.

I guess it's enough to know "too hot", and therefore enough to achieve a meltdown, or partial meltdown, to create steam and potentially so much steam that explosions may occur if pressure isn't released or the material isn't otherwise cooled.

A critical core temperature with nominal coolant in around 500F. Without coolant, she'll go very quickly to 2000F+ Spent fuel? I don't know.

[Donger]

Originally Posted by DJ's left nut

Right, but doesn't that get back to the crux of it?

If the cooling system is fried and nobody seems capable of keeping this water running, what's the end game? They're not going to be able to keep that water constantly surrounding the core, etc, etc...

This seems to be a losing battle they're waging here.

Keeping enough water on the cores to prevent them from becoming exposed until they cool enough so that is no longer a threat.

[teedubya]

Good article explaining radiation etc.

http://www.hps.org/publicinformation...radiation.html

[Amnorix]

CNN update. Not much "new" news.

[6:24 p.m. ET Tuesday, 5:24 a.m. Wednesday in Tokyo] Some context for the new fire in the Fukushima Diiachi nuclear power plant's Reactor 4 building: This is that building's second fire in two days.

The first fire, discovered Tuesday in a cooling pond used for nuclear fuel, coupled with Tuesday's explosion at the plant's No. 2 reactor, briefly pushed radiation levels at the plant to about 167 times the average annual dose of radiation, according to details released by the International Atomic Energy Agency. This chased all but a handful of workers from the site and raised fears of a far more dangerous radiation threat.

Tuesday's dose would quickly dissipate with distance from the plant, and radiation quickly fell back to levels where it posed no immediate public health threat, Chief Cabinet Secretary Yukio Edano said.

The affect that Wednesday's fire was having on radiation levels and information about the fire's cause weren't immediately available. About 200,000 people living within a 12.4-mile radius of the plant have long been evacuated.

Three explosions and two fires have now been reported in various reactor buildings in the past five days.

[Donger]

For the truly panic-stricken, you can always check out Radnet:

http://www.epa.gov/narel/radnet/pdf/...adNet_Data.pdf

[WoodDraw]

Originally Posted by Phobia

Fire has been discovered.... strange way of putting that, I think.

"Around 5:45 a.m., a worker at the plant saw flames on the fourth floor of the reactor's building, believed to be the same spot where an apparent hydrogen explosion caused a fire Tuesday morning in the wake of last Friday's magnitude 9.0 earthquake." - Kyodo reporting: english.kyodonews.jp

Fairly accurate, apparently...


There's some speculation that they can't fight the fire due to radiation levels, so they're bringing in helicopters. That's not confirmed by anyone though.