Excellent explaination of what is happening in the reactors, details on risks

[flamingdem]

http://energyfromthorium.com/2011/03/12/japanese-earthquake-qa1/

Note: the author is pretty pro-nuke so grain of salt, or should I say Iodine?

snip - snip

* Good diagrams at link


At the time of the quake, only three of the units (1, 2, and 3) were operating. They were immediately shut down. Fission stopped. BWRs don’t use borated water and there was no need to add boron to the coolant. The first unit (FD1) appears to have the most difficulties. These older BWRs need emergency power to cool down safely, and their backup generators were damaged by the tsunami. That seems to be the root of the problem.

Q: What about the radiation released? Is it dangerous?

A: It would appear that some of the nuclear fuel in FD1 has melted and released gaseous fission products to the interior of the reactor. These would include xenon, krypton, and iodine. There are about seven isotopes of xenon that are radioactive and would be released in such an incident, with atomic masses of 133, 135, 137, and 138, along with three isomers, 131m, 133m, and 135m. With the exception of the isomers, each of these xenon atoms will decay into cesium and some into other elements past cesium. There is also krypton but its radioactivity and decay products are of less concern.

Xenon itself is not particularly dangerous. It is a noble gas and is not concentrated in the body. Cesium is more of a concern. Here are the seven decay sequences:

Xenon-131m will decay to stable xenon-131.
Xenon-133m will decay to radioactive xenon-133.
Xenon-133 will decay to stable cesium-133.
Xenon-135m will decay to radioactive xenon-135.
Xenon-135 will decay to very mildly radioactive cesium-135.
Xenon-137 will decay to radioactive cesium-137.
Xenon-138 will decay to radioactive cesium-138 and then quickly to stable barium-138.

Of all of these, the decay of xenon-137 to cesium-137 is probably responsible for the most risk, but xenon-137 decays so quickly that the mobility of cesium-137 is limited. I do not think this poses much risk because it can’t get far. The xenon-135 has a longer half-life (9 hours) but decays to a nearly harmless form of cesium (135). I think this poses almost no risk due to the very long half life of cesium-135.

I apologize for this long explanation but you are going to hear the news about cesium being detected and I wanted to tell you why and what it means.

Q: Is nuclear power unsafe?

snip

[Kalun D]

1. Bullship

this guy is way pro nuke, saying no damaging radiation has been released

also this type of reactor has been tested at Sandia labs and has a high failure rate of the primary containment

#2 has already had a breach of the primary containment

all 3 have total failure of secondary containment

all 3 have had low water levels and partial meltdowns

here's the real story from Union of Concerned Scientists

http://allthingsnuclear.org/tagged/Japan_nuclear