Originally, the first link was broken but it is ok now. Poster: thanks for your prompt response and he extra links.
Livermore investigated for nuclear contamination on and off-site
https://www.energy.gov/sites/default/files/2024-01/Notification%20of%20Intent%20to%20Investigate%20Lawrence%20Livermore%20National%20Security.pd
6 comments:
“All team members were tested for exposure,” the NNSA statement said. “Results for some of them showed a detectable uptake of I-125, but at levels well below regulatory and administrative limits, and well below levels of any clinical concern.”
Tested when after initial exposure? Gamma emitting Iodine 125, has a half life of 60 days.
8:15 -- the biological half life matters as well, iodine is retained in the thyroid for several months, but some is excreted more rapidly. It seems to be the testing was within a month or so, so the internal exposure claims are probably true.
Looks like another investigation, just a few weeks ago there was a story on newsline about the Office of Inspector General requesting employee data from LLNS.
September 25, 2023
“Six LANL Employees Tested Positive For Iodine-125 In March Following Foreign Travel As Part Of Multi-Laboratory Team”
https://losalamosreporter.com/2023/09/25/six-lanl-employees-tested-positive-for-iodine-125-in-march-following-foreign-travel-as-part-of-multi-laboratory-team/
“Looks like another investigation, just a few weeks ago there was a story on newsline about the Office of Inspector General requesting employee data from LLNS.”
Regarding what?
Evidently it's a very low energy gamma ray emitter so a NaI scintillator is needed for detection:
https://ehs.umich.edu/wp-content/uploads/2016/04/Iodine-125.pdf
for reference 1 microcurie = 2.2 million dpm approximate (dpm is already corrected for detector efficiciency) so the camera strap was a 2.5 microcurie source at the time measured
If this were ingested, the numbers indicate 3 rem to the thyroid, 125 mrem whole body dose, so not a really large amount of contamination despite the high number of counts:
Committed Dose Equivalent (CDE) - Organ Doses Based on Intake (not uptake)
833 mrem / uCi (thyroid / inhalation / Class "D")
1250 mrem / uCi (thyroid / ingestion / all compounds)
Committed Effective Dose Equivalent: 25 mrem / uCi (WB / inhalation)
(Whole Body / CEDE) 50 mrem / uCi (WB / ingestion)
Annual Limit on Intake (ALI):
40 uCi (all compounds) (ingestion / CDE / 50 rem to Thyroid)
100 uCi (all compounds) (ingestion / CEDE / 5 rem to Whole Body)
60 uCi (all compounds) (inhalation / CDE / 50 rem to Thyroid)
200 uCi (all compounds) (inhalation / CEDE / 5 rem to Whole Body)
[1.0 ALI = 40 uCi (ingested) = 50,000 millirem CDE to Thyroid]
[1.0 ALI = 60 uCi (inhaled) = 50,000 millirem CDE to Thyroid]
[1.0 ALI = 200 uCi (inhaled) = 5,000 millirem CEDE to Whole Body]
Here's an article on thyroid dose limits in general, why they are so high:
https://hps.org/publicinformation/ate/q7303.html
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