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10:42
Preparing an Isotopically Pure 229Th Ion Beam for Studies of 229mTh
Published on: May 3, 2019
Modeling fallout of anthropogenic 129I
Edvard Englund1, Ala Aldahan, Göran Possnert
1Tandem Laboratory, Uppsala University, Box 529, SE-751 20 Uppsala, Sweden. edvard.englund@angstrom.uu.se
Environmental Science & Technology
|January 30, 2009
Summary
This study tracks artificial iodine-129 (¹²⁹I) fallout in Swedish and Finnish sediments from 1942-2006. Results indicate marine sources, like Sellafield and La Hague, significantly impacted North European ¹²⁹I levels, alongside Chernobyl fallout.
Area of Science:
- Environmental Science
- Radiochemistry
- Nuclear Chemistry
Background:
- Anthropogenic iodine-129 (¹²⁹I) emissions are recognized, but temporal fallout patterns and fluxes since the 1940s are poorly understood.
- Sediment archives offer a valuable record for reconstructing past environmental contamination events.
Purpose of the Study:
- To present annual ¹²⁹I concentrations in Swedish and Finnish sediment archives from 1942 to 2006.
- To identify and quantify sources of ¹²⁹I fallout in Northern Europe.
- To estimate the transfer rate of ¹²⁹I from sea to atmosphere.
Main Methods:
- Analysis of annual ¹²⁹I concentrations in sediment cores from Sweden and Finland (1942-2006).
- Numerical modeling incorporating emission rates, fallout, transport pathways, and sediment system dynamics.
- Estimation of ¹²⁹I transfer rates from sea to atmosphere for specific marine regions.
Main Results:
- Sediment records show ¹²⁹I fallout linked to emissions from Sellafield and La Hague nuclear facilities.
- A distinct ¹²⁹I fallout enhancement was observed in 1986, correlating with the Chernobyl disaster.
- Model outcomes suggest a dominant marine source of ¹²⁹I to Northern Europe over direct atmospheric releases.
- A sea-to-atmosphere transfer rate for ¹²⁹I was derived for the English Channel, Irish Sea, and North Sea, ranging from 0.04 to 0.21 y⁻¹.
Conclusions:
- Marine pathways, particularly from reprocessing facilities, are significant contributors to ¹²⁹I contamination in Northern Europe.
- The study provides crucial data on historical ¹²⁹I fallout and its sources, improving our understanding of radionuclide transport.
- Derived transfer rates enhance models for predicting radionuclide behavior in marine and atmospheric environments.
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