Canal-U

Mon compte
Réseau Thématique de Recherche Milieux & Diversité

An interdisciplinary approach in Zone-Atelier Territoires Uranifères (ZATU) to highlight the trace of uranium mining heritage (ZA Territoire Uranifères)


Copier le code pour partager la vidéo :
<div style="position:relative;padding-bottom:56.25%;padding-top:10px;height:0;overflow:hidden;"><iframe src="https://www.canal-u.tv/video/rtr_midi/embed.1/an_interdisciplinary_approach_in_zone_atelier_territoires_uraniferes_zatu_to_highlight_the_trace_of_uranium_mining_heritage_za_territoire_uraniferes.58659?width=100%&amp;height=100%" style="position:absolute;top:0;left:0;width:100%;height: 100%;" width="550" height="306" frameborder="0" allowfullscreen scrolling="no"></iframe></div> Si vous souhaitez partager une séquence, indiquez le début de celle-ci , et copiez le code : h m s
Contacter la chaine
J’aime
Imprimer
partager facebook twitter

An interdisciplinary approach in Zone-Atelier Territoires Uranifères (ZATU) to highlight the trace of uranium mining heritage (ZA Territoire Uranifères)

5e colloque des Zones Ateliers – CNRS 

2000-2020, 20 ans de recherche du Réseau des Zones Ateliers

SESSION 6 - Des observatoires pour suivre les évolutions des socio-écosystèmes


An interdisciplinary approach in Zone-Atelier Territoires Uranifères (ZATU) to highlight the trace of uranium mining heritage (ZA Territoire Uranifères)

Gilles Montavon ∗ 1,2, Alexis Martin 2, Hassan-Loni Yahya 2, Andreas Fichtner 2, Olivier Péron†  2, Karine David 2, Patrick Chardon 3, Sebastien Larrue 4, Alkiviadis Gourgiotis 5, Susanne Sachs 6, Thuro Arnold 6, Bernd Grambow 2, Thorsten Stumpf 6

 

1  LTSER  "Zone Atelier Territoires Uranifères" –  CNRS INEE –  France

2  Laboratoire Subatech  UMR6457 –  add new organisation : IN2P3/CNRS/IMT Atlantique/Université de Nantes –  France

3  Laboratoire de Physique  de Clermont  –  Institut National de Physique  Nucléaire et de Physique  des Particules  du CNRS,  Université Clermont  Auvergne : UMR6533,  Centre National de la Recherche Scientifique : UMR6533 –  France

4  GEOLAB  UMR6042 –  add new organisation : UCA/ Université de Limoges –  4 rue Ledru 63057 Clermont-Ferrand cedex,  France

5  Institut de Radioprotection et de Sûreté Nucléaire (IRSN)  –  PRP-DGE-SRTG-LT2S –  France

6  Helmholt-Zentrum Dresden-Rossendorf,  Institute of Ressource Ecology –  Allemagne


Résumé

Uranium mining and milling activities  as well as mineral processing plants raise environ- mental concerns due to the possible release of radioactive and other potentially toxic elements. Therefore,  their long-term  management  requires knowledge of past events  and a good under- standing of the geochemical mechanisms regulating the mobility of residual radionuclides.  This work presents  the results on the traces and footprints of anthropic activity,  linked to past U mining activities,  within  the vicinity  of Rophin  tailings storage site (Puy  de Dôme,  France). An interdisciplinary approach was developed based on a study of the history and records of the site,  on the radiological and chemical characterization of soil cores and on dendrochronology. Gamma survey  measurements  on the wetland  about 200m  downstream  of Rophin reach 1050 nSv.h-1  that is 3 times the geological background radiation levels.  Soil cores taken in the wet- land showed U concentrations up to 1855 mg.kg-1 that appears to be associated with the presence of a whitish silt loam (WSL)  soil layer located at around 10-30 cm depth below an organic top soil layer.  Records (regulatory documents, inspection reports, letters) supported by former aerial photographs suggest the discharge of U mineral particles during the operation of the site between 1949 and 1957, due to malfunction of the ore washing plant process and the sedimentation step. In accordance with previous findings, analysis of 137Cs and 14C activities date the WSL  layer back to the beginning of the 1950s.  Moreover, lead isotope ratios indicates that contamination in the WSL  layer can be discriminated  by an enrichment  signature with a larger contribution of radiogenic lead to total lead (k = 8.6 ± 0.07 %).  The dendroanalysis permits to link the U emissions from Rophin with the site history using oak tree rings as a suitable bioindicator of changes in bioavailable U concentrations.  Oak tree rings (Quercus petraea ) located downstream of the site contain uranium concentrations up to 50 µg.kg-1,  which is up to ten times higher than values measured from unaffected trees located upstream.   Moreover, highest U concentrations were recorded for the exploitation period but also, more surprisingly,  for the recent makeovers of the Rophin site (2002  and 2010).   This  interdisciplinary  investigation  give clear insights of what happened in the vicinity of Rophin tailings storage site.  All complementary fields of study corroborate that U mineral particles were transported by turbid waters in Rophin’s watershed. While initially transported as mineral particles, at least the majority of the deposited uranium in WSL  layer appears to be trapped in the top soil layer with a high organic matter content. However it evolution should be monitored to understand the the overall dynamics occurring at the site.

 


--

Programme et recueil des résumés à télécharger dans l'onglet documents ci-dessus.

Toutes les informations sur le site du colloque :

https://20ans-rza.sciencesconf.org/resource/page/id/5


 

commentaires


Ajouter un commentaire Lire les commentaires
*Les champs suivis d’un astérisque sont obligatoires.
Aucun commentaire sur cette vidéo pour le moment (les commentaires font l’objet d’une modération)
 

Dans la même collection

FMSH
 
Facebook Twitter
Mon Compte