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The 'why I am not worried' article, edited by MIT nuclear scientists

mitnse.com

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Re: The 'why I am not worried' article, edited by MIT nuclear scientists

#41
post #11

Earlier quoted context omitted.

So, there's still nobody hurt then? I hope so.

There are reports of two missing: http://www.hindustantimes.com/Fresh-fire-at-Japan-nuclear-re...

Well, there are thousands missing elsewhere, I just hope that anyone alive gets found.

Re: The 'why I am not worried' article, edited by MIT nuclear scientists

#42
post #12

This was quite a 'walk-back' of the original headline. It started as "Why I am not worried about Japan’s nuclear reactors" on one site. The title is now "Modified version of original post written by Josef Oehmen", with the content modified and moved to another site. It also now includes a disclaimer "Note that the title of the original blog does not reflect the views of the authors of the site." Perhaps they should j…

Just remember that the "original" was a blog post quoting an email posted by someone other than the writer---the "original" title was not the author of the email's.

Re: The 'why I am not worried' article, edited by MIT nuclear scientists

#43

Earlier quoted context omitted.

Here you go: Original: http://pastebin.com/UnCYDKbu Modified: http://pastebin.com/1BAV3A4s Good online tool to compare both: http://text-compare.com/ Sorry, the tool above doesn't offer a direct link to the diff, so you'll have to do the copy/paste by yourself. Or you could use pastebin's own diff, but it's less clear, in my opinion: http://pastebin.com/diff.php?i=1BAV3A4s

Try this for a side-by-side diff: http://dl.dropbox.com/u/171026/japan-nuclear-diff.html I produced this using a feature of WinMerge (graphical diff utility for Windows, not too shabby) which can produce an HTML report of a diff. The revisions seem pretty significant.

or: how I learned to stop not worrying and love the daiichi.

Very interesting, thanks.

Re: The 'why I am not worried' article, edited by MIT nuclear scientists

#44
post #22

Earlier quoted context omitted.

Well the fact that it was necessary to be revised, should give you a hint that some things were wrong with the original one.

From the looks of the diff, it appears as though all they did was add clarity. Not really revise any of the facts.

I notice that they removed the implication that this reactor design incorporated a core catcher.

Re: The 'why I am not worried' article, edited by MIT nuclear scientists

#45

Earlier quoted context omitted.

The worst case scenarios are bad: If one reactor gets so bad (meltdown) forcing permanent evacuation - all the remaining reactors won't be maintainable/saveable and thus in a domino effect - if one goes, all go (meltdown). It is unlikely that a meltdown through the core will occur but if that happens - the scary term China Syndrome - the melted radioactive fuel will melt through steel, concrete, rock, maybe even bedr…

Why would one meltdown cause evacuation? The meltdown would still be contained

Why would one meltdown cause evacuation?

Because of fire, explosions, and excessive radiation exposure to workers.

The meltdown would still be contained

Containment is believed to have failed in reactor 2 and likely 3 at this point. Smoke or steam has been billowing from number 3 for hours now and its fuel is in the reactor, not the spent fuel pool.

Re: The 'why I am not worried' article, edited by MIT nuclear scientists

#46
post #11
post #10

CNN and MSNBC are now reporting that all workers have now been evacuated from Fukushima due to rising radiation levels.

So, there's still nobody hurt then? I hope so.

5 dead, 2 missing, 22 injured (including some severely).

http://www.nytimes.com/2011/03/16/world/asia/16workers.html?...

Re: The 'why I am not worried' article, edited by MIT nuclear scientists

#47
post #8

Meanwhile, 2 days after this article was published on March 13: "A small crew of technicians, braving radiation and fire, became the only people remaining at the Fukushima Daiichi Nuclear Power Station on Tuesday — and perhaps Japan’s last chance of preventing a broader nuclear catastrophe." http://www.nytimes.com/2011/03/16/world/asia/16workers.html?...

They have just been pulled out because of increased radiation. http://news.ycombinator.com/item?id=2330500

They're still there and working on the plant. http://thelede.blogs.nytimes.com/2011/03/15/latest-updates-o...

Re: The 'why I am not worried' article, edited by MIT nuclear scientists

#48
post #36

Earlier quoted context omitted.

I heard one supposed expert on CNN basically state that a nuclear meltdown is no big deal. He's right, in a sense. Modern nuclear reactors are designed so that if the fuel melts it will end up in a wide concrete tray which sits under the reactor, where -- thanks to the fact that the tray is very wide and not at all deep -- it will cool down to a safe temperature. All good engineering works on the principle of defence…

"All good engineering works on the principle of defence in depth." That line is as much a sound-bite at this point as anything you'll hear on cable television. Yes, good engineering has many levels of fall-backs and redundancies. But when you've reached the point that you've evacuated the last fifty people from your site because it's no longer safe for them to be there , then you've exhausted your defenses. There's n…

Maybe the "wide concrete tray" will capture the waste. Maybe it won't.

Maybe the laws of physics will change, but I'd be willing to bet that they won't.

But in the meantime, you're hoping that there's not a secondary fire from the heat

Concrete doesn't burn.

or a steam explosion

At the point when the nuclear fuel melts, all the water has boiled off 1000 degrees ago.

or some other kind of explosion that flings radioactive particulate for miles around.

Explosions don't just happen for no reason.

You're hoping that the fuel won't melt, form a critical mass in the bottom of the reactor, and re-initiate a reaction that's hard to stop.

Nuclear reactors don't hold enough fuel to form a critical mass. In order to become critical, they need a moderator (usually water) which thermalizes neutrons.

Re: The 'why I am not worried' article, edited by MIT nuclear scientists

#49
post #23

I'm really kind of sick of listening to people talk about how everything is hunky-dory. I heard one supposed expert on CNN basically state that a nuclear meltdown is no big deal. The lesson to learn here is when a government tells you everything is ok regarding an event with potential regional impact, get the hell out of town. I'm assuming the reactors are melting down and are out of control. Pumping seawater in may…

According to the IAEA, Reactors 1-3 have been in cold shutdown since yesterday, which means they finally are where they were supposed to end up, in a stable situation where no water is boiling off anymore, so all the risk is gone.

Re: The 'why I am not worried' article, edited by MIT nuclear scientists

#50
This is BULLSHIT, the guy (Oehmen) is a mechanical engineer with a management focus. He worked at my alma mater (ETHZ). His field of experties is supply chain risk management. Look up his papers, he isn't a nuclear physicist.

I'd say he's about as qualified to make a comment on the situation as I am.

The "essay" by Oehmen was first published by a notorious nuclear lobbyist, Jason Morgan. Look at this: http://nuclearfissionary.com/about/

  Nuclear Energy suffers from a poor public image. We’re here to change all that.

  For decades the nuclear energy industry has been under attack 
  by antinuclear activists both organized and unorganized. 
  Fear and panic have been their call signs and with little 
  regard for science or the impact on civilization, they   
  have remained unchecked for years
And more, from that page:

  Jason Morgan

  A corporate finance and accounting professional 
  who has great personal interest in the future of 
  the world’s energy crisis. Jason is looking forward 
  to utilizing his financial and economic data 
  analysis skills to shed light on nuclear energy.


In short: FUD by nuclear energy lobbyists.
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