Re: Potassium Iodide -Reply -Reply

[Emil <kerremba@pilot.msu.edu>]

Mike,
It is an interesting question.
I hope you do not feel that it is inappropriate for me sending your
question to radsafe?
I thought, it may be interested to other on radsafe as well.


>You say > 1 h and < 1 day. But many of the iodine isotopes have half lives
>of several days. Am I misunderstanding something?
>
>The Chernobyl reactor was xenon poisoned, but it still emitted a lot of iodine.
>
>I would be grateful if you could help me to understand this. thanks, mike

"Shlala gashle" (Zulu greeting, meaning "Stay safe")
mike (mcnaught@LANL.GOV)


kerremba@pilot.msu.edu
 
I understand your confusion, I thought about the half lifes too.
Unfortunaly, I was not in Chernobyl in May of 1986 and do not know the
exact iodine isotopic ratio in the fall out neither I sow the data.
 
.." <1 day"..  I picked up from my reactor experience, it is
roughly when xeson poisoning is decreased to the resonable level. But it
could be 2 days
it depends on the total risk assessment. I would not like to kill with
KI one person
but safe ten teens from thyroid suffering. It is more moral question. I
think it should be based on scientific calculations and optimization
process between two risk factors
radiation from iodine and KI side effects. And keep in mind the cost of
the future liabilities.
Fortunely my personal reactor experience does not include any incidents
by any degree close to that in 1986. 
 ..>1 hour.. I have choosed to allow more time for xenon poisoning to
progress, it is a differential process and the exact time needs to be
determined considernig other factors too, the human factor I would
consider too, we need to give time for personal to react in resonable
time. The real xenon poisoning of course will happen much sonner.
..> The Chernobyl reactor was xenon poisoned,....
About the degree of the xenon poisoning in forth reactor I have some
questions. If it was ONLY the steam explosion then reactor was in the
condition which has no significant xenon poisoning at the starting point
of the accident but if there were involved other factors then cituation
with posoning was different. While I was there I heard a few different
versions. Some of them more speculative them others. I have one of mine
own, but I would not put it on radsafe without conclusive data to suport
it. Internet has enough crap without me.

Two years after the 1986 accident I started trying to reconstruct the
reactor and fuel conditions during the 1986 accident based on radio
isotopic concentrations of long lived radionuclides in " hot " particles
which we found around the reactor inside as well
as outside 10 km and 30 km zones up to 60 km in 1988-1991, its
coordinats and correlate it to the time when it was throwed out from the
reactor, using meteriological (weather conditions) data, particles and
reactor physical conditions..etc. I thought it could be a good theme for
my dissertation. But personal and other circumstances, luck of data on
short lived radionuclides, iodine one of them, did not allow me to
finished that particular project. I thing some data on iodine could be
used from far way from the Chernobyl, because iodine has a good
volatility and low evaporation temperature.

I still have some questions about which Iodine??? would be depleted, it
may effect risk calculation. If it is only I-131  it is one scenario if
it is only I-134 which I
suspect could be a possibility then it would be different. I guess we
will have to used the same quality factor for all of them any way but
the the half lifes will be different.

Because of that I am very interested to hear more opinions on this
subject from others. 
I will look more in my papers, these constant movings do not help me to
keep every thing in order and I will think and try to dig in my memory
deeper. I thought, I left
that period of my life far behind..


Best regards,
Emil.    


It is still so nice to represent your own opinion and not your
employer's when
you do not have one.