On 18/02/2013 17:05, Tim Streater wrote:
In article ,
John Rumm wrote:

On 18/02/2013 00:12, Windmill wrote:
polygonum writes:

On 17/02/2013 05:43, Windmill wrote:

But they give iodine tablets to those exposed.
What does I131 decay to? Is it also radioactive? If so, what in
turn is
its half-life?

The whole point of iodine tablets is to provide all the iodine that
the
person's thyroid needs using known non-radio-active iodine. Thus the
thyroid will not take up any radio-active iodine in the environment.

Do bear in mind that thyroid hormone is then distributed to every cell
of the body so radio-active iodine is a wonderful way of giving
people a
dose of radiation to their entire body! (Whereas a modest excess
iodine/iodide can often be excreted quite readily. And hopefully the
radio-active iodine would be so excreted.)

(Technically, they often use Potassium iodide.)

Understood, but there must be a feeling that there may still be enough
I131 around to cause trouble, even weeks or months later.
Otherwise they wouldn't bother.

Maybe my question should have been not to ask what I131 decays to, but
rather what decays to I131.

Cadmium 131 and 132, and Tellurium. (presumably from the cladding of
fuel rods rather than anything directly in the uranium decay chain)

I-131 decays to Xenon-131 (stable). According to Winky, I-131 is a major
decay product of uranium fission.

Do you have a reference, I could not find iodine in any of the Uranium
decay chains I looked at - perhaps I am missing one?

--
Cheers,

John.

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