Change of radioactive cesium (137Cs and 134Cs) content in cloud water at an elevated site in France, before and after the Fukushima nuclear accident: Comparison with radioactivity in rainwater and in aerosol particles
GURRIARAN, R.
Institut de Radioprotection et de Sûreté Nucléaire [IRSN]
Centre d'Etudes Nucléaires de Bordeaux Gradignan [CENBG]
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Institut de Radioprotection et de Sûreté Nucléaire [IRSN]
Centre d'Etudes Nucléaires de Bordeaux Gradignan [CENBG]
Langue
en
Article de revue
Ce document a été publié dans
Atmospheric Research. 2015-01, vol. 151, p. 45-51
Elsevier
Résumé en anglais
Airborne cesium isotopes (134Cs and 137Cs) released during the Fukushima nuclear accident were transported all around the world attached to particles and reached France about 12 days after the first explosion. Concentration ...Lire la suite >
Airborne cesium isotopes (134Cs and 137Cs) released during the Fukushima nuclear accident were transported all around the world attached to particles and reached France about 12 days after the first explosion. Concentration of cesium isotopes in cloud water sampled at the summit of the Puy de Dôme mountain (1465 m a.s.l.) increased by a factor of at least 40. During the following weeks, the concentrations decreased more slowly in cloud water than in rain and in rain compared with what was found on the aerosol phase. Cesium-134 was detectable in the aerosol phase, in rain and in cloud water for 3 months, 11 months and 18 months after the accident, respectively. These kinetics are consistent with the washout scavenging of aerosol in the lower layers of the atmosphere that leads to a relative depletion of Fukushima-labeled aerosols at ground level. Airborne particles at high altitudes, i.e. where clouds form, have a longer residence time. This finding has implications on the different time scales at which a contamination may be transferred to the ground, depending if it is transferred via dry or wet deposition. This study highlights that cloud water is a relevant type of environmental sample to attest the presence of radionuclides on a longer time scale than for the aerosol phase, provided that the metrology is able to lower usual detection limits. Rainout efficiency was computed for 137Cs.< Réduire
Mots clés en anglais
Aerosol
Cloud
Droplet
137Cs
Fukushima
France
Origine
Importé de halUnités de recherche