Discharge of dissolved and particulate137Cs in the Kuji River, Japan
1991; Elsevier BV; Volume: 6; Issue: 2 Linguagem: Inglês
10.1016/0883-2927(91)90026-l
ISSN1872-9134
AutoresTakeshi Matsunaga, H. Amano, Nobuyuki Yanase,
Tópico(s)Marine and coastal ecosystems
ResumoThe discharge of fallout137Cs in the water of the Kuji River was studied with the aim of understanding the migration behavior of137Cs in the river watershed. Under normal flow conditions, the radioactivity of dissolved137Cs in the water ranged from 0.05 to 0.12 mBq/l, while that of the particulate137Cs ranged from 0.02 to 0.09 mBq/l. A large increase in the particulate137Cs, up to 0.77 mBq/l, was observed under high flow conditions caused by a 40 mm precipitation event. It was found that the dominant speciation of137Cs changed from the dissolved to the particulate mode according to the flow conditions related to the precipitation event. The annual budget of137Cs in the watershed was estimated based on empirical relation between the load of137Cs and the flow rate. The accumulated137Cs in the watershed was evaluated as 4.2 × 103 MBq/km2. On the other hand, the annual losses were 1.7 MBq/km2 by the discharge into the river and 1 × 102 MBq/km2 by radioactive decay. This budget has proved, qualitatively, that the surface soil acts as a significant adsorbant for atmospherically-derived137Cs.
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