Regional and global contributions of anthropogenic iodine-129 in monthly deposition samples collected in North East Japan between 2006 and 2015.
J Environ Radioact
; 171: 65-73, 2017 May.
Article
en En
| MEDLINE
| ID: mdl-28187334
ABSTRACT
We measured the monthly atmospheric deposition flux of 129I at Rokkasho, Aomori, Japan-the location of a commercial spent nuclear fuel reprocessing plant-from 2006 to 2015 to assess the impact of the plant on environmental 129I levels. The plant is now under final safety assessment by a national authority after test operation using actual spent nuclear fuel. During cutting and chemical processing in test operations from April 2006 to October 2008, 129I was discharged to the atmosphere and detected in our deposition samples. 129I deposition fluxes largely followed the discharge pattern of 129I from the plant to the atmosphere, and most of the deposited 129I originated from the plant. In and after 2009, 129I deposition fluxes decreased dramatically to reach the background level; the 129I deposition fluxes at Rokkasho were almost the same as those at Hirosaki, where an additional sampling point was set up as a background site 85 km from the plant in 2011. The background 129I deposition fluxes showed seasonal variation-high in winter and low in the other seasons-at both Rokkasho and Hirosaki. The results of a backward trajectory analysis of the air mass at Rokkasho suggested that reprocessing plants in Europe were the origins of the high 129I flux in winter. The contribution of 129I released from the Fukushima Dai-ichi Nuclear Power Plant accident to the 129I deposition flux at Rokkasho in 2011 was small on the basis of the 129I/131I activity ratio.
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Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Monitoreo de Radiación
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Contaminantes Radiactivos del Aire
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Contaminación Radiactiva del Aire
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Accidente Nuclear de Fukushima
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Radioisótopos de Yodo
País/Región como asunto:
Asia
Idioma:
En
Revista:
J Environ Radioact
Asunto de la revista:
SAUDE AMBIENTAL
Año:
2017
Tipo del documento:
Article