Nuclear Meltdown Japan

[Sanibel]

Just wanted to start a topic in case people wanted to discuss possible precautions against potential nuclear fallout from the Japan disaster.

So far the word is no direct radioactive fallout will reach the US, but the full meltdown potential hasn't happened yet.

Just starting a topic in case people have any information to share.

[gtalum]

This event isn't likely to equal the Chernobyl event, thus there will be no significant effects in the US.

[RL3AO]

The longer we go without a major leak the better. The short term half life material is already starting to break down. Thats the bad stuff. Everyone likes to point out the million year half life stuff, but in reality its not that dangerous unless you live with it for an extended period of time. It just doesn't break down quick enough to cause you problems.

[Stephanie]

This event isn't likely to equal the Chernobyl event, thus there will be no significant effects in the US.

Now with 4 fires going and one of them is in the waste storage area, it's starting to seem like it may be a Chernobyl event. I hope those 50 brave souls that stayed behind can pull off a miracle.

[fanlynne]

The true heros of the world are the Japanese people who continue to work at these plants despite the danger. They are truely putting their lives on the line for a noble cause and humanity in general. A very hard time for the families whose parents are making this sacrifice.

[Ptarmigan]

The longer we go without a major leak the better. The short term half life material is already starting to break down. Thats the bad stuff. Everyone likes to point out the million year half life stuff, but in reality its not that dangerous unless you live with it for an extended period of time. It just doesn't break down quick enough to cause you problems.

Radioactive materials with really short or long half life are not that dangerous either they decay too fast or are stable. It is the ones in between, with half life in the thousands of years that are dangerous.

[MGC]

Alpha, Beta, Gamma pick your poison...just read the the workers at the nuke plants are being pulled out. Since the reactors are close to the ocean, a total meltdown into the water table would produce an radioactive steam cloud which would disperse into the atmosphere. Radioactive isotopes could travel with the wind. I remember the nuke tests years ago produced some fallout over the USA......MGC

[Crostorm]

New news from kyodo news
URGENT: Radiation briefly topped 10 millisievert at Fukushima plant
TOKYO, March 16, Kyodo

The radiation level at the quake-hit Fukushima No.1 nuclear power plant reached 10 millisievert per hour at one point Wednesday morning, possibly due to the damage at its No.2 reactor the day before, the government's nuclear safety agency said.

The maximum level was measured at the plant's front gate at 10:40 a.m. It fell to 6.4 millisievert at 10:45 a.m. and to 2.3 millisievert at 10:54 a.m. but rose again to about 3.4 millisievert as of 11:00 a.m., the Nuclear and Industrial Safety Agency said.

==Kyodo

[Sanibel]

Trouble is they chose to store the spent rods in a tank on the top of unit #4. If I have this right that unit is overheating which will boil-off the water surrounding the material. The inevitable fire that occurs from that uranium mass going critical will create a fire that will make a seriously radioactive cloud similar to the worst Cesium 137 cloud exploded-out in Chernobyl. Frankly, when they say "no Chernobyl" I think they are only being technical in that there will be no explosion, however there will be a similar release of identical materials only in smoke-off form rather than exploded. - Not good.

The only advantage here is the ocean is the best place for that cloud to fall-out over and will best absorb it over the long-term (if it happens).

Media said today "the west coast will see some raised levels in radiation from this".

They need to get some water into those tanks as soon as possible. Trouble is media says there is possibly 50 yard wide death zone from radioactivity forming around some of the reactors.

[vbhoutex]

Please source your info. We are getting different takes on what will or won't happen here in the US and for that matter Japan. Not doubting what you are saying, just trying to sort it all out.

[Sanibel]

There's almost nothing on the internet giving the specifics.

Believe it or not what I typed was gotten from interviews with the head of the US Nuclear Regulatory Agency, head MIT expert on nuclear energy, and other international nuclear agency officials on MSNBC, CNN, and FOX News.

[Sanibel]

From another site - The Japanese say the spent fuel rod pond won't go critical:

"It is not realistic now to think that the No. 4 reactor at a quake-damaged nuclear power plant in northeastern Japan will "reach criticality," the chief government spokesman said on Wednesday." http://www.reuters.com/article/2011/03/ ... NX20110316

That is not reassuring to me. A few days ago it was supposedly unrealistic that any of this would happen.
To even think that fuel in a pond could possibly go critical, meaning start nuclear fission, is frightening. Apparently though they've got a whole reactorload of only partly expended fuel in that pool. So what's keeping it from going critical and fissioning? Apparently the fuel rods are spaced apart far enough so that won't happen. As long as they are intact. Also have borated water surrounding the rods, boron a good fission damper. That fire though: Burning fuel rods apparently, burning because the water level went down too far. Will burning fuel rods turn to slag and slump to the bottom of the pool and collect into a massive enough but still compact enough lump to go critical?

[gtalum]

Alpha, Beta, Gamma pick your poison...just read the the workers at the nuke plants are being pulled out. Since the reactors are close to the ocean, a total meltdown into the water table would produce an radioactive steam cloud which would disperse into the atmosphere. Radioactive isotopes could travel with the wind. I remember the nuke tests years ago produced some fallout over the USA......MGC

There's fallout and there's fallout. You mentioned the three types of radiation, alpha beta and gamma. There are very big differences between the three, and there are big differences in their toxicity. There are also big differences in the daughter materials spawned and the radiation they emit.

As for "meltdown into the water table", that's physically impossible in this situation. A meltdown is not the end of the world scenario posited by many. It's REALLY bad for the local region, but only marginally bad for everyone else, a lot like Chernobyl was. Since these reactors were not fissioning at the time of the initial failures, and aren't fissioning now, it's also impossible for them to emit radiation in a quantity even remotely like what occurred at Chernobyl.

We're looking at a worst case scenario somewhere between Three Mile Island (which it's already surpassed) and well short of Chernobyl.

[Sanibel]

A guy in the business on another site says 2 reactors' cores are now at 75% damaged. He says the #'s 5 & 6 plants are at 85c and should start boiling-off their water soon.


They are trying to rig a high voltage electric cable to restart the emergency cooling pumps.


They are going to use high pressure fire hoses on ladder trucks to spray water onto the reactors from a safe distance.

[angelwing]

I got this via a "before its news" tweet, I don't know..what do you think?

Radiation from the Fukishima Daiichi nuclear power plant disaster has reached Alaska, according to the state commissioner of health and social services in that state. He said the state has detected a “very small increase in radiation levels – well below levels that would be a health concern.”

“Right now, we don’t expect any radiation to affect Alaska,” Chris Laborde, the state’s emergency program manager, told KTVA in Alaska.

State bureaucrats failed to note that the amount of radiation that has reached Alaska is from the smaller magnitude release from the stricken plant last week. Since then, the plant has released considerably more radiation after explosions and fires ravaged the site in Fukushima. It takes several days for prevailing winds to deliver the radiation across the Pacific Ocean.

http://beforeitsnews.com/story/486/708/ ... laska.html

[MGC]

I read that only the #4 reactor was shutdown at the time of the quake...so, the other 3 reactors were at operational temperature. A retired sailor at work who happens to have been a reactor operator on subs told me that it takes a long time for the reactor to cool even with coolant flow. Without coolant flow the heat will continue to build in the reactor core even if the reactor had been SCRAMed. Fission continues all the time and a small amount of heat is generated over time until it reaches the melting point. I use to live right down the road from Waterford 3 nuke plant in Louisiana and read up on the worst case which was a core meltdown which will eventually melt the primary containment vessel, the concrete base and into the earth. Why will this not happen in this case?....MGC

[Sanibel]

CORRECTION:


Wrong info in my last post. Plants # 5 & 6 are the ones at 85c not #4.


The nuclear engineer on the other site says 2 containments are breached now and venting to the outside atmosphere.

[jasons2k]

I'm just not confident in the 'official' news coming out of Japan. This has already been upgraded to a Level 6 disaster, one level below Chernobyl:

http://www.reuters.com/article/2011/03/ ... M920110315

Time is running out to cool those reactors.

[RL3AO]

I'm just not confident in the 'official' news coming out of Japan. This has already been upgraded to a Level 6 disaster, one level below Chernobyl:

Well, thats not official. Its just the French saying this looks like a 6.

This is the only 6 in history. An explosion at a Soviet reprocessing plant in 1957.

"Explosion

In September 1957 the cooling system in one of the tanks containing about 70–80 tons of radioactive waste failed, and the temperature in it started to rise, resulting in a non-nuclear explosion of the dried waste having a force estimated at about 70–100 tons of TNT, which threw the concrete lid, weighing 160 tons, into the air.[2] There were no immediate casualties as a result of the explosion, which released an estimated 2 to 50 MCi (74 to 1850 PBq ) of radioactivity.[1][3][4]

In the next 10 to 11 hours the radioactive cloud moved towards the northeast, reaching 300–350 kilometers from the accident. The fallout of the cloud resulted in a long-term contamination of an area of more than 800 square kilometers, primarily with caesium-137 and strontium-90.[1] This area is usually referred to as the East-Ural Radioactive Trace (EURT).[5]
[edit] Aftermath

Because of the secrecy surrounding Mayak, the population of affected areas were not initially informed of the accident. A week later (on 6 October) an operation for evacuating 10,000 people from the affected area started, still without giving an explanation of the reasons for evacuation. People "grew hysterical with fear with the incidence of unknown 'mysterious' diseases breaking out. Victims were seen with skin 'sloughing off' their faces, hands and other exposed parts of their bodies."[6] It was Zhores Medvedev who revealed the nature and extent of the disaster to the world.

Even though the Soviet government suppressed information about the figures, it is estimated that the direct exposure to radiation caused at least 200 cases of death from cancer.[7]"

IMO, this sounds much worse then what we have now. So it's probably a 5.

[dixiebreeze]

http://www.nytimes.com/2011/03/17/scien ... .html?_r=1

Possibly southern California by Friday