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Merged nuclear power safe?

technoextreme said:
You really don't know much about electrical engineering do you. Most of the world's generators would probably end up blowing the cooling systems to smithereens. Hell Japan is special in the regard that the generators located in half the counntry would blow up the cooling systems.

Hah!!!! Says the guy whose suggesting that they physically blow up the cooling systems.
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I would seriously doubt they run the industrial equipment at 100VAC.
 
bobdroege7 said:
My point was that levels at the site boundary are 2500 times high enough to require evacuation using a radiation level one half of the lowest one you just posted.
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By what calculation ? Background level in average are 2.5 mSv/Year which is 0.28 micro Sv per hour. At the edge it was last time I checked 300 Micro Sv per hour. That is 1000 time at most and the 2.5 is an average, in some city it is much higher due to several factor. Secondly seeing how quickly it fall off , from reactor to edge, I seriously doubt any claim of "necessary evacuation" without real measurement of the source (are those escaping highly radioactive but very short half life gas ? Are those longer half life element ? Is that a point source at a reactor ?).

Once you made a visit there , and made measurement radioactivity remote from the plant, and demonstrated that the contamination require medium term evacuation (as opposed to a few days), or point to an official source saying the same, you will have a point.

But until now all i see is opinion, which are not better than ours, the french guy one, or any one opinion not there fighting the meltdown or in official fashion.
 
technoextreme said:
Also, you are completely wrong. I actually double checked this before calling you out on your BS. Only an idiot melts aluminum in open atmosphere.
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That will include all those idiots who happily melt Al scrap in their garages and back yards to make Al castings then? What was the nature of your "double check"? Just put casting aluminium into Google.

Ship superstructures, aircraft etc etc made of aluminium alloy cannot burn.
 
GlennB said:
Ship superstructures, aircraft etc etc made of aluminium alloy cannot burn.
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glennb,
All due respect, but there is a difference between melting point, boiling point and ignition point.

Measurements has been made of the ignition temperature of three structural metals in bulk form in a pure oxygen environment. Cylindrical specimens 5 mm in diameter and 5 mm high were ignited by a focused cwCOz laser beam in a static

oxygen environment at pressures from 0.084 to 6.895 MPa. A two-color pyrometer was designed and used to measure the ignition temperature of the specimens. The temperature of a spot approximately 0.5 mm in diameter located at the center of the specimen top surface was recorded with a maximum time resolution of 25 μs and with an accuracy of a few percent.

The results showed that 6061 aluminum alloy ignited at temperatures well above the melting temperature of pure aluminum but below the melting temperature of Al2o3.

The ignition temperature of 302 stainless steel was approximately at the melting temperature of the alloy and the ignition temperature of 1018 carb on steel was slightly below the melting temperature of the alloy. In all three cases there was a mild dependance of ignition temperature on oxygen pressure.

http://www.informaworld.com/smpp/content~db=all~content=a776653639
 
Listening to Letters and Politics right now. Their expert is saying that they put spent fuel in swimming pools. He's used the term "swimming pool" at least eight times so far. How often do people swim in these pools?
 
pipelineaudio said:
Listening to Letters and Politics right now. Their expert is saying that they put spent fuel in swimming pools. He's used the term "swimming pool" at least eight times so far. How often do people swim in these pools?
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Probably trying to make it easier to understand for lay people.

You can't swim too much in those things.
Causes bleeding gums and hair-loss.
 
http://www.jaif.or.jp/english/news_images/pdf/ENGNEWS01_1300433768P.pdf

The "Containment Vessel Integrity" for reactor 2 is still listed as "Damage Suspected" while that status for reactor 3 has been changed to ""Might be ”Not damaged”"

"Remarks: Immediate threat is damage of the fuels in the fuel pool outside the containment vessel at Unit-1,2,3 and 4. The operation for filling the pool with water has been conducted since March 17 at Unit-3."

It also says "Attempting to receive external power supply, TEPCO is laying a power cable between the transmission line and Unit-2."

Although there were some media reports that power lines had been connected that appears to be slightly premature.

Several attempts were made again today to spray water into the pool of reactor 3 with high power fire trucks. (TV reports tentatively reported that this spraying operation may have resulted in a drop in radiation levels.)
Diesel generators are still operating to pump water into reactors 5 and 6
 
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GlennB said:
That will include all those idiots who happily melt Al scrap in their garages and back yards to make Al castings then? What was the nature of your "double check"? Just put casting aluminium into Google.

Ship superstructures, aircraft etc etc made of aluminium alloy cannot burn.
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Skwinty said:
glennb,
All due respect, but there is a difference between melting point, boiling point and ignition point.
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I know, but ....

Skwinty said:
Measurements has been made of the ignition temperature of three structural metals in bulk form in a pure oxygen environment. Cylindrical specimens 5 mm in diameter and 5 mm high were ignited by a focused cwCOz laser beam in a static oxygen environment at pressures from 0.084 to 6.895 MPa. A two-color pyrometer was designed and used to measure the ignition temperature of the specimens. The temperature of a spot approximately 0.5 mm in diameter located at the center of the specimen top surface was recorded with a maximum time resolution of 25 μs and with an accuracy of a few percent.
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Makes perfect sense to me, but note the bolded bits. The fact remains that aluminium structures will not reach ignition temperature in even the hottest standard fire and would need an oxygen atmosphere even if, somehow, they did. Al is perfectly safe in fires from the p-o-v of its combustion. It will, of course, melt pretty easily in a vigorous building fire. That was all I was trying to point out in my orginal response :)
 
GlennB said:
That was all I was trying to point out in my orginal response :)
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No sweat,GlennB.:)

ETA: Interesting side point. Thin zirconium will ignite just with a high pressure oxygen blast.
I will find the paper for that and post a link.

ETA2: In continuation of an investigation of the spontaneous ignition of titanium, the behavior of zirconium was determined. It was found that zirconium sheet, varying in thickness from 0.010 to 0.250 in., could be ignited by exposing it rapidly to oxygen under pressure. The ignition limits, in terms of oxygen pressure and concentration, necessary to produce spontaneous ignition, were determined for zirconium and Zircaloy.

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B759D-48NCDNR-2R6&_user=10&_coverDate=10%2F31%2F1961&_rdoc=1&_fmt=high&_orig=gateway&_origin=gateway&_sort=d&_docanchor=&view=c&_searchStrId=1683826496&_rerunOrigin=google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=3fc814a4258a73d6457edbd1db7f5f03&searchtype=a
 
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BobTheDonkey said:
So the French are on the ground at the reactors dealing with the actual data/readings from local equipment?

Maybe that's why this is such a problem. Stupid French, they're not known for engineering prowess...


:rolleyes:
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France has the worlds most well developed civilian nuclear power generation program. More than three quarters of their electricity comes from nuclear power. In the nuclear community, few question their expertise and experience.

If the french (and by this I mean french engineers, not activists and media) are considering Fukushima a 6, then I would give their opinion serious consideration.
 
Sword_Of_Truth said:
France has the worlds most well developed civilian nuclear power generation program. More than three quarters of their electricity comes from nuclear power. In the nuclear community, few question their expertise and experience.

If the french (and by this I mean french engineers, not activists and media) are considering Fukushima a 6, then I would give their opinion serious consideration.
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I don't care on their experience, or whatever *authority* they have in it, if they are not there , and have no data beyond what the Japan governement give, then they have no way to assess it except from picture, and from what I can read gfrom the assessement from 5 to 7 , a picture is not enough.

FFS, I read that some US guy estimated an INES 7. From what ? Picture ?
 
BobTheDonkey said:
So the French are on the ground at the reactors dealing with the actual data/readings from local equipment?

Maybe that's why this is such a problem. Stupid French, they're not known for engineering prowess...


:rolleyes:
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Given the poor quality of information coming from the site to date, I don't think we can trust their assessment. The official expert American reports have been very alarming. The incident is without doubt much more serious than TMI.
 
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