Jose is likely wrong. Even if the worst possible contamination happens,
all life on earth will not cease next year, much less in the near
future. Insects, bacteria, and some other life-forms are incredibly
more resistant to the effects of ionizing radiation than are the higher
life forms. That being said, studies of survivors of Hiroshima and
Nagasaki showed a surprisingly and unexpected low incidence of birth
defects and sterilization. The greatest risk seems to be an elevated
incidence of cancers, primarily among the survivors (who did not
continue to be contaminated after a relatively short period of time) and
a lesser increase in cancers than the norm among their offspring.
Therefore, total meltdowns with long-term, wide spread, impossible to
clean-up contamination will cause a very real threat to the continuation
of our life expectancy (and that of higher life-forms) for a very long
time into the future, but probably not eradicate any species.

The total amount of extremely radioactive, uncontrolled, very hot, spent
reactor fuel in the 4 badly damaged pools in the reactor buildings plus
the 3 badly damaged reactor cores is huge. Each spent fuel pool is
probably holding the equivalent of at least 4 fully loaded reactor cores
and that spent irradiated fuel is much more radioactive and dangerous if
released than the fuel inside each of the 3 damaged cores.

The power plant is essentially on a beach. A full fuel melt down through
the bottom of the plant of any of these 7 collections of out of control
fuel rods will put multi-thousand degree molten, incredibly radioactive
material in direct contact with the pacific ocean once the fuel burns
through the sand (the temperature is high enough to fully and easily
liquefy sand). The resulting steam explosion is likely to disperse far
more radioactivity than multiple Chernobyls.

The big problem is not I-131. The half-life of that isotope is only 8
days, and uptake can be blocked by appropriate use of potassium iodide
until environmental levels return to a safe level. A much larger
problem is Cesium-137, which has a half-life of 30 years, is water
soluble and therefore taken up by all the plants and animals in our
environment.

Also released will be Strontium-90, which behaves like calcium and is
taken up into the bones and teeth and has a half-life of almost 29 years.

Plutonium isotopes are released, which decay into several much more
dangerous isotopes of Americium, one of which has a half life of 7,370
years. This stuff is an alpha particle emitter, which is almost
harmless when outside the body but is highly carcinogenic from the inside.

If this incredibly radioactive brew comes into direct contact with the
Pacific Ocean, it will be easily and relatively rapidly spread
throughout the world. Although the dilution factor will be tremendous,
the total amount of very long-lived radioactive matter will also be
tremendous. There is no way to predict how many of the 7 at-risk
collections may go to full melt-down, but if even a few do, the
world-wide consequences could be huge for tens of thousands of years.

It will not be Armageddon, but will probably be the worst disaster the
planet has endured since the great meteor crash approx. 65 million years
ago.

In article , Peter
wrote:

Each spent fuel pool is
probably holding the equivalent of at least 4 fully loaded reactor cores
and that spent irradiated fuel is much more radioactive and dangerous if
released than the fuel inside each of the 3 damaged cores.

These statements are completely contradictory to what I've been hearing
lately. First, the spent rods are far *less* radioactive than the ones
in the core. That's why they're *spent.*

Second, the tonnage of spent and active rods in all six reactors was
given out, and IIRC it's only slightly more than a 1:1 ratio. So your
"probably" can be edited to read "not even close to."

Given those basic glaring errors, it's hard to ascribe much credibility
to the rest of your alarmism.

On 3/17/2011 1:01 PM, Smitty Two wrote:
In ,
wrote:

Each spent fuel pool is
probably holding the equivalent of at least 4 fully loaded reactor cores
and that spent irradiated fuel is much more radioactive and dangerous if
released than the fuel inside each of the 3 damaged cores.

These statements are completely contradictory to what I've been hearing
lately. First, the spent rods are far *less* radioactive than the ones
in the core. That's why they're *spent.*

Second, the tonnage of spent and active rods in all six reactors was
given out, and IIRC it's only slightly more than a 1:1 ratio. So your
"probably" can be edited to read "not even close to."

Given those basic glaring errors, it's hard to ascribe much credibility
to the rest of your alarmism.

Spent fuel means that too much of the original quantity of U-235 in the
control rods has been transmuted by neutron bombardment to other
isotopes that do not respond efficiently to neutron bombardment by
giving off more neutrons. Therefore, they do not have the ability to
sustain an efficient chain reaction that is needed to produce enough
heat to enable the core to function efficiently in their configured
geometry as a power source. It does not mean that their radioactive
emissions have been spent.

U-235 (in subcritical quantities) produces a lot less high energy beta
and gamma irradiation than do many of the transmuted isotopes that are
present in spent fuel. Although unwise, it is possible to bare-handle a
new commericial power plant uranium fuel pellet for a limited period of
time without any significant danger. (Wash your hands well afterward,
as uranium is a heavy metal and you can be chemically poisoned by it.)
However, even brief unshielded exposure to spent fuel pellets can yield
a fatal dose of radiation.

As far as my "alarmism", I head this AM on NHK TV an interview with a
Japanese nuclear scientist who admitted that it was unlikely, but not
impossible that a fuel melt-down in one of out of control locations
could go critical - meaning that you would not have a steam explosion,
you would have an atomic bomb go off.

Smitty Two - I am not going to start waving credentials, but I suspect
that I have substantially more formal and practical experience dealing
with nuclear power and radiation health issues than you do. Your basic
misunderstanding of "spent fuel" reveals your lack of knowledge in the
field.

In article , Peter
wrote:


Smitty Two - I am not going to start waving credentials, but I suspect
that I have substantially more formal and practical experience dealing
with nuclear power and radiation health issues than you do. Your basic
misunderstanding of "spent fuel" reveals your lack of knowledge in the
field.

You present as scholarly in the field, so I have no doubt that you're
far more qualified than I. I stand corrected on the radioactivity of the
spent rods; I was reporting what I'd heard. As far as quantity of rods,
like I said, the tonnage of spent and active in each reactor is known;
said ratio is much closer to 1:1 than it is 4:1.

As far as your alarmism, that's not really quantifiable or debatable,
but a matter of personal interpretation. Your last two paragraphs offer
a scenario that's orders of magnitude more catastrophic than anything
any nuclear expert I've heard or read has offered. I call that alarmism.
YMMV.

"Peter" wrote in message
...
stuff snipped
As far as my "alarmism", I head this AM on NHK TV an interview with a
Japanese nuclear scientist who admitted that it was unlikely, but not
impossible that a fuel melt-down in one of out of control locations
could go critical - meaning that you would not have a steam explosion,
you would have an atomic bomb go off.

That would make the Japanese the only victims of three atomic explosions.
Twice by us, once by themselves - that's just incredibly bad luck. I am
sure they'll be blaming GE just a little bit if it happens.

I read a similar report but it also said that a number of very unlikely
events would have to occur in an unlikely sequence. In other words, not
very likely. The problem is how do you truly estimate the odds of any
outcome with the serious lack of knowledge about the internal states of
these reactors? How do you know what to do next when this is the first
event to unfold exactly this way?

Where are all the miracle robots that Japan is famous for creating? A
couple of them roaming around inside the reactor might make decision making
by TPTB a lot easier, providing both eyes and limited action capabilities.
I wouldn't want to be any one of the people charged with fixing this mess.
I'll bet more than a few get heart attacks from the stress. Think of the
worst thing you've ever done and compare it to the nuclear mess in Japan.
Ahhh! I'm feeling less guilty already.

--
Bobby G.

It will not be Armageddon, but will probably be the worst disaster the
planet has endured since the great meteor crash approx. 65 million years
ago.

I thought I saw Armageddon knock over and dig through my garbage can last
night. No wait, that was a raccoon.

never mind.

On 3/18/2011 1:23 PM, Robert Green wrote:


Where are all the miracle robots that Japan is famous for creating? A
couple of them roaming around inside the reactor might make decision making
by TPTB a lot easier, providing both eyes and limited action capabilities.
I wouldn't want to be any one of the people charged with fixing this mess.
I'll bet more than a few get heart attacks from the stress. Think of the
worst thing you've ever done and compare it to the nuclear mess in Japan.
Ahhh! I'm feeling less guilty already.

--
Bobby G.



Unfortunately, the limited views of the interior of the reactor
buildings that have been obtained from overhead satellites and
helicopters show such extensive rubble that even a highly mobile robot
would probably not be able to navigate successfully inside. In
addition, the unbelievably high levels of radiation at the close
distances the robots would need to work would likely disable the robot's
circuit boards and video camera sensors. In short, what we've got here
is an incredible mess.

If the cooling systems fail to work adequately after restoration of
electrical power, (I think the probability is poor that the cooling
systems will work effectively at all 4 damaged sites; too great a
likelihood of cracked pipes and cracked containment vessels), the most
likely way to resolve the situation will be total entombment with
concrete and sand - a la Chernobyl.

Yes, the incredibly brave volunteer workers who have remained on site
are unbelievably altruistic. I suspect that not all of them will
survive long term without serious health consequences and at least some
of them may not survive long term.

On 3/18/2011 2:05 PM, Iowna Uass wrote:
It will not be Armageddon, but will probably be the worst disaster the
planet has endured since the great meteor crash approx. 65 million years
ago.

I thought I saw Armageddon knock over and dig through my garbage can last
night. No wait, that was a raccoon.

never mind.



Armageddon sure is a funny name for a raccoon. Hey, that's a good name
for a hyper puppy dog. ^_^

TDD

In article ,
wrote:

You might know something, or just be a know it all who knows nothing.
But what the governments are saying is hogwash too. They are already
experiencing a nuclear winter near the power plants.
See:
http://www.thejackonline.org/mobile/...-pon-1.2516579

Your source is a college newspaper in the pot capital of the U.S.? A
Humboldt County college kid quoting a text message on a cell phone in
Tokyo that says "don't trust the media?"

I'm dumbfounded.

On Mar 18, 1:23*pm, "Robert Green" wrote:
"Peter" wrote in message

...
stuff snipped

As far as my "alarmism", I head this AM on NHK TV an interview with a
Japanese nuclear scientist who admitted that it was unlikely, but not
impossible that a fuel melt-down in one of out of control locations
could go critical - meaning that you would not have a steam explosion,
you would have an atomic bomb go off.

That would make the Japanese the only victims of three atomic explosions.
Twice by us, once by themselves - that's just incredibly bad luck. *I am
sure they'll be blaming GE just a little bit if it happens.

I read a similar report but it also said that a number of very unlikely
events would have to occur in an unlikely sequence.

I guess that sequencde would include the reactor figuring out how to
enrich the U-235 from a few percent up to the 90+% required for
a nuclear explosion. Witnessing the difficulty entire nations like
Iran and North Korea appear to be having doing that, I think it
unlikely that a melting blob in the bottom of the reactor vessel is
going to achieve that.





*In other words, not
very likely. *The problem is how do you truly estimate the odds of any
outcome with the serious lack of knowledge about the internal states of
these reactors? *How do you know what to do next when this is the first
event to unfold exactly this way?

Where are all the miracle robots that Japan is famous for creating? *A
couple of them roaming around inside the reactor might make decision making
by TPTB a lot easier, providing both eyes and limited action capabilities..
I wouldn't want to be any one of the people charged with fixing this mess..
I'll bet more than a few get heart attacks from the stress. Think of the
worst thing you've ever done and compare it to the nuclear mess in Japan.
Ahhh! *I'm feeling less guilty already.

--
Bobby G.

Peter wrote:

As far as my "alarmism", I head this AM on NHK TV an interview with a
Japanese nuclear scientist who admitted that it was unlikely, but not
impossible that a fuel melt-down in one of out of control locations
could go critical - meaning that you would not have a steam explosion,
you would have an atomic bomb go off.


In an atom bomb you have to make the materials supercritical *very*
rapidly. You can't do that in a reactor. Every source I have ever read
is that you can have a heat explosion but that a nuclear explosion is
impossible. For instance heat causes materials vaporize with rapid gas
expansion (explosion). The material is blown apart faster than it came
together. Such a heat explosion would scatter very radioactive material
and be a major disaster.

--
bud--

On Sat, 19 Mar 2011 09:13:29 -0600, bud--
wrote:

Peter wrote:

As far as my "alarmism", I head this AM on NHK TV an interview with a
Japanese nuclear scientist who admitted that it was unlikely, but not
impossible that a fuel melt-down in one of out of control locations
could go critical - meaning that you would not have a steam explosion,
you would have an atomic bomb go off.


In an atom bomb you have to make the materials supercritical *very*
rapidly. You can't do that in a reactor.

No you can't. In an atom bomb, they surround the nuclear material
with a sphere of conventional explosive, and when that detonates, it
compresses the smaller sphere inside. There is nothing remotely like
that in a power plant, where all there is is some hot material used to
heat water to run the turbines that make electricity. No other
explosives.

Every source I have ever read
is that you can have a heat explosion but that a nuclear explosion is
impossible. For instance heat causes materials vaporize with rapid gas
expansion (explosion). The material is blown apart faster than it came
together. Such a heat explosion would scatter very radioactive material
and be a major disaster.

On 3/19/2011 11:13 AM, bud-- wrote:
Peter wrote:

As far as my "alarmism", I head this AM on NHK TV an interview with a
Japanese nuclear scientist who admitted that it was unlikely, but not
impossible that a fuel melt-down in one of out of control locations
could go critical - meaning that you would not have a steam explosion,
you would have an atomic bomb go off.


In an atom bomb you have to make the materials supercritical *very*
rapidly. You can't do that in a reactor. Every source I have ever read
is that you can have a heat explosion but that a nuclear explosion is
impossible. For instance heat causes materials vaporize with rapid gas
expansion (explosion). The material is blown apart faster than it came
together. Such a heat explosion would scatter very radioactive material
and be a major disaster.


The risk of supercriticality depends upon the level of U-235 enrichment,
the overall mass of the enriched uranium, the presence of mutated
isotopes in the rods, the specific geometry, and the concentration of Pu
if you are using MOX (Fukashima's reactor #3). I agree completely that
at the 3-5% U-235 that Japan claims it uses, and that is used in most
nuclear reactors, a supercriticality seems impossible. However, I
suspect that no one has ever "done the experiment" with a large melted
core containing MOX instead of just uranium. I too would not have given
the claim I mentioned ANY credence if it had not come from a Japanese
nuclear engineer. I figure maybe they know something that has not been
made available to the public at large.

The need to use high explosives to rapidly implode the fissile material
is somewhat related to the total mass of fissile material that you are
trying to get to go supercritical. The most "efficient" weapons will
use relatively small amounts of highly enriched fissile material to
enable feasible shielding and transport of the weapon. However, when
you are talking about tons of fissile mass, as in a core meltdown,
rather than pounds, you are dealing with a different scenario. We all
hope that the assumptions behind the predictions are based upon accurate
theory and calculations and that a supercriticality in the event of any
type of power plant core meltdown is an absolute impossibility.