Sunday, March 13, 2011

Will they try top-kill or golf balls next?

"TOKYO — Japanese officials struggled on Sunday to contain a widening nuclear crisis in the aftermath of a devastating earthquake and tsunami, saying they presumed that partial meltdowns had occurred at two crippled reactors and that they were bracing for a second explosion, even as they faced serious cooling problems at four more reactors." NY Times

I am no expert, and also a large fan of nuclear power for certain purposes. For space exploration, the production of radioactive isotopes, for research, and even power generation under the right conditions, I think nuclear power is very useful. But all the same, I am shocked that we are still not able to scram a civilian reactor sufficiently and put it in a configuration in which it no longer generates even a few percentage points of operational heat. Even if that means having an emergency configuration in which the entire core and vessel is split into a few pieces that can be moved far apart or dropped into a tank of water and reactor poison (neutron poison) like boron. Further, as said in a previous post, it is hard to imagine that there is no emergency method for the cooling of a core by totally passive means such as a reservoir or in this case, by seawater. It should be automatically activated when the generator system fails. In addition, if triple redundancy is to be had for generator systems, three identical generators in the same location cannot be considered suitable. Each generator must be a different type, and located in a different place. One should be on the ground, the other high in the air (to prevent damage from tsunamis which, yes, come from the Ocean sometimes.) The third should be underground or indoors and resistant to attack by humans.

Basically, it seems as if the ability to react to a disaster near a nuclear power plant (earthquake, flood, tsunami, terrorist attack) has not changed much since 9-11, not changed much since April 26th, 1986, not changed much since March 28th, 1979. And all the while, experts proclaim that another accident is simply impossible. Yet all it takes is a temporary loss of power, plus the failure of a few identical generators (all vulnerable to the same fault), for several cores to meltdown (Chernobyl) and hydrogen explosions (Three Mile Island) to damage power plant infrastructure. As usual, these experts either profited from the expansion of the nuclear power industry, or were simply unwilling to imagine scenarios in which humans were unable to anticipate things like earthquakes and tsunamis in Japan. What language is "tsunami" anyway?


david.schultz said...

It is very likely that the reactors were shut down. But just because you shut down the fission of uranium does not stop the process. The fission products continue to decay and will produce large amounts of heat for quite some time. There is nothing you can do to stop that.

But there are designs that do not require active cooling in this situation. Not that it makes any difference as these are ancient designs. (1960's)

What boggles my mind is that they have this heat source which is still producing steam and they are dependent on backup generators.

Arjan said...

It's a contraction of two Japanese words
'tsu' = harbour
'nami'= (high) wave

Hearing Voices said...
This comment has been removed by the author.
R2K said...

The reactors were shutdown, but I mean to say there should be some way to (even if it means destruction of the core) put it in a stable cooling situation, or even bury it in sand. Anything other than hey just spray it with water forever and hope it does not melt down.

A fair question is: Should old reactors still be active at a time when people are flying planes into things? I see little reason why a similar problem could not have been caused by a high-speed impact of a large jet into the containment dome. A direct hit could, with a bit of luck, damage the cooling system or even rupture the pressure vessel. And all of the guys who have been saying there is no way a jet could cause that kind of damage, were the same ones who suggested that this kind of multiple meltdown could also not happen.

They are also saying that this is not, and will never be a Chernobyl. I agree that an excursion, steam explosion, and fire on that scale are unlikely. But hardly impossible.