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It's been missing for 4 weeks, actually...

Economics is politics by other means
by Migeru (migeru at eurotrib dot com) on Sat Jun 11th, 2011 at 02:42:13 AM EST
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Japan Earthquake Registered Only 6.67 - Nuclear Induced Tsunami - Japan Offers Iran Enriched Uranium - An Act of War? - Japan: Knife At Its Throat : Abel Danger

2. Reactor 4 is building 7, demolished by explosives. [爆発物によって破壊された] Reactor 4 had been defueled and was undergoing replacement of it's internal stainless steel shroud, yet blew it's containment anyway. That is the FINAL smoking gun, an empty reactor is inert, and cannot produce an explosion, yet one happened at 4 that was so powerful it destroyed the structure leaving it in danger of falling over. Overheated open fuel pools cannot produce hydrogen because in an open fuel pool the water boils off at 100 Celsius, and won't be present in pressurized form at 2,000 degrees Celsius to liberate it's hydrogen by losing it's oxygen to the zircon cladding in the fuel rods. The rods will prefer the free oxygen in the air and burn long before attempting to claim the oxygen in whatever humidity there might be. The fact that the rods can catch fire only enforces the fact that they cannot release hydrogen in open air the way they can in a reactor. If you entertain the fantasy that they could, another problem against buildup presents itself - the hydrogen would be safely burned the moment it was created on the surface of the superheated rods. There would be no buildup. Fuel rods are many orders of magnitude below incapable of going supercritical also, even if totally melted down. The explosion at #4 was flatly impossible.

Reactor 4's dome was removed for defueling. Drone photos prove it. This dispels the rumors surrounding unit 4's explosion. Some people have said that this reactor was secretly in operation to enrich plutonium. This photo proves it was disassembled for shroud replacement as stated. Tepco is going out of it's way trying to explain the explosions, especially at reactor 4, because they did indeed occur, so an explanation is needed. As a result, they are giving reasons that cannot happen, just to say something.

have fun debunking, science wonks!

'The history of public debt is full of irony. It rarely follows our ideas of order and justice.' Thomas Piketty

by melo (melometa4(at)gmail.com) on Mon Jun 13th, 2011 at 08:52:57 AM EST
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Just the title is hilarious... regarding the No. 4 hydrogen explosion, see upthread.

Overheated open fuel pools cannot produce hydrogen because in an open fuel pool the water boils off at 100 Celsius, and won't be present in pressurized form at 2,000 degrees Celsius to liberate it's hydrogen by losing it's oxygen to the zircon cladding in the fuel rods.The rods will prefer the free oxygen in the air and burn long before attempting to claim the oxygen in whatever humidity there might be.

Just to piece together all that has been mixed up above:

  • 2,000°C was the estimated maximum temperature of exposed fuel rods in the core of some of the reactors, not the reaction temperature of steam;
  • the zircalloy cladding starts reacting with water below 800°C,
  • unlike zirconium powder, zircalloy cladding will not burn (it will oxidise alright, but will not ignite even at melting temperature),
  • pressure is less relevant to reaction rate than density, and less density doesn't mean no reaction just slower reaction,
  • water evaporating from the pool and rising up in it is very well present to react with the fuel rods,
  • however, the current theory abiout the origin of the exploded hydrogen is no more the spent fuel pool (its evaporation wasn't as dramatic by the time of the explosion), but hydrogen from No. 3: the venting pipes of both No. 3 and No. 4 unite and exit into the same exhaust stack, thus part of the hydrogen exiting No. 3 could  flow 'in reverse' into No. 4.


*Lunatic*, n.
One whose delusions are out of fashion.
by DoDo on Mon Jun 13th, 2011 at 09:31:20 AM EST
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