Development of 129I AMS at the Nuclear Science Laboratory for Sampling in the Great Lakes Region

¹²⁹I in the environment primarily comes from its release from nuclear fuel reprocessing centers in Europe. Iodine moves through the environment very easily as it is highly soluble and easily incorporated into biological organisms. This high mobility makes ¹²⁹I an excellent environmental tracer in a variety of fields including geology, nuclear forensics, and nuclear safeguards. However, because of its long half-life of 15.7 Myr, detection of ¹²⁹I through direct decay counting methods is often unachievable because of the sample size that would be required. Accelerator mass spectrometry (AMS), on the other hand, is well suited to the detection of ¹²⁹I as it can identify individual ions through isotopic and isobaric discrimination. The environmental sampling throughout the United States has been primarily limited to the areas surrounding nuclear facilities, but there are few measurements of the concentrations of ¹²⁹I throughout the rest of the country. This has inspired the AMS group of the Nuclear Science Laboratory at the University of Notre Dame to measure the concentrations in the Great Lakes region to establish a baseline for measuring the change of these concentrations in the future. Preliminary results of ¹²⁹I measurements and future plans will be discussed.

This work is supported by the NSF through Grant Number PHY-1713857.