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Tepco engineers use concrete to seal leaks  (Source: TEPCO)
The top five feet of the core's 13 ft-long fuel rods had melted down after being exposed to the air

The Tokyo Electric Power Company (Tepco) has announced that the No. 1 reactor at the Fukushima Daiichi nuclear power plant has suffered a nuclear meltdown.

The Fukushima Daiichi nuclear power plant was first commissioned in 1971 and is located in the Futaba District of Fukushima Prefecture, Japan. On March 11, 2011, a 9.0-magnitude earthquake struck Japan, resulting in the disabling of reactor cooling systems, radiation leaks and an evacuation zone. 

Engineers from Tepco entered the No. 1 reactor for the first time at the end of last week and found that the top five feet of the core's 13 ft-long fuel rods had melted down after being exposed to the air. 

Engineers originally thought only 55 percent of the core was damaged since it was submerged in enough water to keep cool and stable, but after discovering a pool of molten fuel at the bottom of the containment vessel, they now worry that this molten fuel burned a hole at the bottom of the vessel prompting water to leak. 

Tepco recently sealed a leak at the No. 3 reactor after radioactive water had seeped into the ocean. Also, the No. 2 reactor had radioactive water flowing into the ocean in April. According to Greenpeace, "significant amounts" of radioactive material had slipped into the sea. In fact, illegal amounts of iodine and caesium were found in seaweed as far as 40 miles from the Fukushima Daiichi plant. 

In 22 samples of seaweed, ten contained five times the legal limit of iodine 131 and 20 times of caesium 137. This is an issue for several reasons, including the fact that the Japanese household consumes almost 7 lbs of seaweed annually, and fisherman are preparing to harvest this seaweed on May 20. 

Engineers have decided to quit flooding the entire reactor core with water because it might make the leak worse. Currently, there is plenty of water at the bottom of the containment vessel to keep the remaining fuel rods and the melted fuel cool. 

"We will have to revise our plans," said Junichi Matsumoto, Tepco spokesman. "We cannot deny the possibility that a hole in the pressure vessel caused water to leak."


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Yay!!
By mkrech on 5/13/2011 5:51:26 PM , Rating: 0
New foes for Godzilla.

to soon?




RE: Yay!!
By Lanister on 5/13/2011 6:16:10 PM , Rating: 2
yes, too soon. IMHO a good guideline is if people are still suffering due to a disaster then it's too soon to make light of.


RE: Yay!!
By ppardee on 5/13/2011 7:13:17 PM , Rating: 2
So, with a half-life of uranium at 4.47 billion years, we have roughly 13 billion years to wait before we can make jokes?

Or maybe we can start in 150 years when the Cs-137 decays to acceptable levels?

Or we can just grow more seaweed. It seems pretty good at sucking up the bad stuff. Almost like nature has a way of neutralizing bad things in the environment...


RE: Yay!!
By Ushio01 on 5/13/2011 7:41:53 PM , Rating: 1
quote:
Or maybe we can start in 150 years when the Cs-137 decays to acceptable levels?


You mean 70 days.


RE: Yay!!
By PaterPelligrino on 5/13/2011 8:21:07 PM , Rating: 2
The phrase "decays to acceptable levels" is vague enough to offer a lot of wriggle room, and I'm not sure what the answer to that is; however, the half-life of Cesium-137 is 30 years.

It is the biological half-life of Cesium-137 that is 70 days, meaning that 70 days after ingestion , it loses half of it's radioactive toxicity through elimination, etc.

The Cesium-137 released by the Chernobyl meltdown 20 years ago is still a threat to human health.


RE: Yay!!
By randomly on 5/13/2011 8:30:50 PM , Rating: 3
Cs-137 has a 30 year half life. In 150 years 97% will have decayed away.

Almost none of it will have decayed in 70 days.

You may be thinking of the iodine-131 which has an 8 day half life. Only 1 part in a thousand will be left after 80 days, in 160 days only 1 millionth of the I-131 will be left, including whatever was in the seaweed.

Although the CS-137 lasts much longer, the iodine is more of a concern because of how strongly the body absorbs and concentrates it in the thyroid. CS-137 is thousands of times less hazardous because it's not readily absorbed or concentrated in tissues to the degree that iodine is.

Fortunately there will be almost no radioactive iodine left in a few months. Only about 1/200th of the original I-131 is left currently.

on the other hand your comment about 70 days is also partly valid since radiation levels for almost all areas except the plant itself are already fairly low.


RE: Yay!!
By drewsup on 5/15/11, Rating: 0
RE: Yay!!
By Solandri on 5/13/2011 8:49:32 PM , Rating: 5
quote:
So, with a half-life of uranium at 4.47 billion years, we have roughly 13 billion years to wait before we can make jokes?

This is a common misconception among people who don't really understand radioactivity.

Stuff with a really long half-life (thousands of years or longer) is relatively safe. Yes they're radioactive, but the long half-life means it emits the radiation so slowly that your exposure from handling it even for days is limited.

Stuff with a really short half-life (a few seconds to a few months) is also relatively safe. Put it behind some shielding and wait a while, and most of it has decayed into something else which emits no radiation or a lot less radiation. If you get exposed to it when it's fresh, then you have problems. But it only stays fresh for a short period. This stuff was why radiation levels were so much higher right next to the reactors than in the surrounding area. By the time these substances got carried by the air to the surroundings, enough time had passed that they'd decayed into harmless or relatively harmless substances.

It's the stuff with intermediate half-life which is dangerous. It's not short enough to become safe relatively quickly, and it's not long enough that the decay happens slowly enough to make it safe to handle. Stuff with half-lives of a few years to a hundred years or so falls into this category.

Iodine-131 has a half-life of 8 days. So for the first few weeks it's dangerous. After that, the remaining amount is so small that it's safe. Its decay product is stable Xenon-131.

Cesium-137 is a real problem. It has a half-life of 30 years. It's a beta emitter, but decays into a form of Barium-137 which gamma decays almost immediately. The worst of both worlds - a long half-life with a double decay emission.

For this reason, Cesium-137 and Strontium-90 are the primary radioactive byproducts of concern from a nuclear accident. Due to the nature of the accident, there wasn't a lot of Strontium-90 (29-year half-life) released as was in Chernobyl. That stuff builds up in your bones, contaminating you for life if you're exposed.


RE: Yay!!
By Angstromm on 5/14/2011 3:36:14 AM , Rating: 3
quote:
yes, too soon. IMHO a good guideline is if people are still suffering due to a disaster then it's too soon to make light of.


While I appreciate the sensitivity and compassion this response suggests, I want to add that humor is sometimes profoundly cathartic. Context is, I suppose, import as well. All I can say is, I so appreciated those friends who joked with me, and with whom I could joke, when my wife died in the Cedar Fire (in SoCal, '03). Laughter in the midst of profound heartache was, for me, a gift and helped me trust that I could go anywhere or say/share anything with those friends/family who could joke or get my jokes, despite the horrific circumstances.


RE: Yay!!
By SunTzu on 5/15/2011 12:44:47 PM , Rating: 2
I doubt the jokes revolved around how nice your wife smelled while being barbequed though, which is kind of what this could be seen as.

I think you should be able to joke about anything, but i wouldnt tell a joke about how fun radiation poisoning is to someone who's hair was currently falling out :P


RE: Yay!!
By Angstromm on 5/15/2011 2:21:52 PM , Rating: 2
I do tend to agree with you--as I said, context plays a part. If you know someone well, jokes, for instance, about my wife smelling like a barbeque could very well have their place (and there were jokes of a similar nature, so yr wrong on that account).

For me, I wouldn't be inclined to put a limit or cap on the sorts of jokes that my close friends say to me or that I might say to them under terrible circumstances. But then we love and understand one another well. Telling such jokes to a stranger could have disastrous effects. Depends. Again, circumstances and context. Sometimes going there--telling that "sick" joke--is exactly the right things to do. Sometimes one blows it and steps over the line. I never experienced that w/ my friends/family after my wife died.

As a side note, I work as a therapist/counselor with cancer patients and their families. Sometimes the joking gets pretty intense, but in my years of doing this work, I've never had a client tell me that we/I went over the line. Most express relief and appreciation for having room to "go there." Mind you, I'm not saying that I joke w/ all my clients or that they all joke w/ me. Some don't go there at all and I wouldn't dream of joking w/ some clients. Again, context.

Bottom line for me is: humor can be a very powerful tool for helping each other process the unimaginable. It sometimes allows us to say the unsayable. Sometimes it helps us to re-see the situation or experience it from a different perspective. Sometimes it allows us to say what we all know everyone is thinking but are afraid to say. Humor can be a way into the most tender, vulnerable and painful parts of human experience and therefor profoundly cathartic.

I'm not saying it's always right/apropos or always effective. But for me, in my life, there's always room for humor, having friends poke at my faults, stupidity, arrogance, whatever. I utterly delight in this sort of thing and am grateful I have those around me that care enough and are perceptive enough to call me on my shit in ways that also help me laugh at myself. Pretty powerful. But I don't assume that others are like me and want the same from me (theme of context, again).


RE: Yay!!
By tng on 5/16/2011 7:58:41 AM , Rating: 2
Well to be truthful, the first thing I thought of when they said that the reactor was leaking radioactive water into the Pacific was "Oh Crap", followed closely by "Isn't that how the lizard that became Godzilla was mutated?".

It is funny when something like this syncs up to a 50 year old cartoon, even in the face of profound tragedy. Not sure if I could really like or even get along with someone who could not laugh at the humor in a situation like this. Life it to short....


RE: Yay!!
By Belard on 5/13/11, Rating: 0
RE: Yay!!
By Integral9 on 5/16/2011 9:15:54 AM , Rating: 2
Naa... http://www.youtube.com/watch?v=jHPOzQzk9Qo
So with that in mind:

Oh nooooos.... it's Seaweed Thing and it's friend, Sumo Clam with it's Pearl of Power.. we must leave now.


"And boy have we patented it!" -- Steve Jobs, Macworld 2007














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