The 15.7 million year question iodine 129

Submitted by Anonymous on Fri, 2011-08-05 13:35

Question for brawm team do u have the capability to see this isotope?seems like a way larger problem than short lived Iodine 131 any thoughts?

‹ Real Time Radiation Monitoring; clickable map What effect will there likely be on the US from the current highest yet readings ›

I-129, because of its much

Submitted by tjaucott on Fri, 2011-08-05 14:15.

I-129, because of its much longer half-life, won't be anywhere near as radioactive as I-131. 16 million years vs. 8 days is a factor of 700 million times less radioactivity.

In fact, we don't have to measure it directly to know how much I-129 is here. We could do a detailed ORIGEN calculation to find the exact number, or we could estimate from the fission yields that there was at least 30 million times less radioactivity from I-129.

Even at the highest levels of iodine in our rain in March, this is still less than 10^-6 Bq/L. This level of activity is too low for us to measure, even with our very low detectability limits.

Will it stay around longer? Yes, but the amounts will continue to get smaller as they are spread in the environment, and even at their peak, these levels are millions of times less dangerous than our natural background doses.

Tim [BRAWM Team Member]

http://neutroneconomy.blogspo

Submitted by Anonymous (not verified) on Fri, 2011-08-05 13:43.

http://neutroneconomy.blogspot.com/2011/03/situation-stabilizing-at-fuku...

"Chemically active species such as iodine are one of the more serious concerns for contamination, as iodine is readily absorbed by the human body (and rapidly taken into the thyroid); this is the basis for using potassium-iodine tablets as a "prophylactic" measure, flooding the thyroid with natural (non-radioactive) iodine such to prevent the uptake of the radioactive species. Iodine in fission products generally falls into two species - iodine-131, which has a half-life of 8 days, and iodine-129, which has a half-life of 15.7 million years. Only iodine-131 is of any serious contamination concern, given the extremely long half-life of iodine-129 (which means the activity from this species is extremely low). (Iodine-129, while being inconsequential to short-term dose, is an isotope of concern for geologic repositories, given its long lifetime and iodine's ease of movement in groundwater.)"

I am still concerned.