Measurement of 129I/127I isotopic ratios in sea and fresh water samples by MILEA

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21340%2F23%3A00366995" target="_blank" >RIV/68407700:21340/23:00366995 - isvavai.cz</a>

Result on the web

<a href="https://static.akcongress.com/downloads/ranc/ranc2023-boa.pdf" target="_blank" >https://static.akcongress.com/downloads/ranc/ranc2023-boa.pdf</a>

DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Measurement of 129I/127I isotopic ratios in sea and fresh water samples by MILEA

Original language description

The majority of 129I (with a half-life of 15.7 My) in the environment comes from human nuclear activity, especially from reprocessing facilities of nuclear fuel. In this work seawater and freshwater samples collected by DTU (Technical University of Denmark) were used and processed. Iodine was separated from pre-treated water samples with solvent extraction and subsequent precipitation as AgI. Measurement of the iodine concentration in each sample by ICP-MS took place at DTU. Within this work, the first batch of iodine samples were separated from environmental water samples in Denmark and prepared as AgI which were then pressed in copper target cathodes and measured at the MILEA (Multi Isotope Low Energy AMS) system at LIP, ETH Zürich, Switzerland. Measured 129I/127I atomic ratios range from 1x10-7 to 2x10-6. Higher 129I concentrations in seawater samples collected from the North Sea comparing to in the samples collected from the Baltic Sea was observed. This corresponds with the known dominant source of 129I in this region - reprocessing plants at La Hague (France) and Sellafield (United Kingdom), which was discharged into the marine environment. Iodine-129 labeled water is transported by sea current to the north along the European coast. Small part also enters in the North Atlantic Ocean and causes increased concentration of 129I there. The main part of 129I in North Atlantic Ocean was originated from nuclear weapons fallout [1]. The measurements show that the 129I/127I ratios for seawater samples from Greenland seas varies from 2x10-8 to 4x10-9 and for seawater surrounding the Faroe Islands was 5-10x10-10. The results show that 129I serves as a good oceanographic tracer for monitoring water mass exchange [2]. Values for freshwater samples, specifically Danish rivers, reached ratios of 1x10-8 - 4x10-9.

Czech name

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Czech description

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Type

O - Miscellaneous

CEP classification

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OECD FORD branch

10402 - Inorganic and nuclear chemistry

Project

<a href="/en/project/EF16_019%2F0000728" target="_blank" >EF16_019/0000728: Ultra-trace isotope research in social and environmental studies using accelerator mass spectrometry</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>S - Specificky vyzkum na vysokych skolach

Publication year

2023

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů