Radiocesium distribution of above- and under-ground parts of wild vegetable ().

Ito, Satomi; Sasaki, Yoshito; Niizato, Tadafumi; Watanabe, Takayoshi; Mitachi, Katsuaki*

KEK Proceedings 2019-2, p.132 - 137, 2019/11

no abstracts in English

Status of study of long-term assessment of transport of radioactive contaminants in the environment of Fukushima (FY2018)

Nagao, Fumiya; Niizato, Tadafumi; Sasaki, Yoshito; Ito, Satomi; Watanabe, Takayoshi; Dohi, Terumi; Nakanishi, Takahiro; Sakuma, Kazuyuki; Hagiwara, Hiroki; Funaki, Hironori; et al.

JAEA-Research 2019-002, 235 Pages, 2019/08

JAEA-Research-2019-002.pdf:21.04MB

The accident of the Fukushima Daiichi Nuclear Power Station (hereinafter referred to 1F), Tokyo Electric Power Company Holdings, Inc. occurred due to the Great East Japan Earthquake, Sanriku offshore earthquake, of 9.0 magnitude and the accompanying tsunami. As a result, large amount of radioactive materials was released into the environment. Under these circumstances, JAEA has been conducting Long-term Environmental Dynamics Research concerning radioactive materials released in environment, especially migration behavior of radioactive cesium since November 2012. This report is a summary of the research results that have been obtained in environmental dynamics research conducted by JAEA in Fukushima Prefecture.

5 years monitoring results for the environmental dynamics of radiocesium in mountainous forest of the Abukuma Mountains, Fukushima

Niizato, Tadafumi; Watanabe, Takayoshi; Mitachi, Katsuaki*; Sasaki, Yoshito; Ito, Satomi; Abe, Hironobu

no journal, , 

An understanding of long-term environmental dynamics of radiocesium, which is released by the TEPCO's Fukushima Dai-ichi Nuclear Power Plant accident, is a key issue for predicting the future radiocesium distribution and forest products radioactivity in a forested environment, especially Cs with half-life of 30 years. We compiled the five-years monitoring results of radiocesium input-output budgets in broad-leaved deciduous forests and Japanese cedar evergreen forests of the Abukuma Mountains, Fukushima, Japan. The input-output rates were a few percent of the radiocesium inventory of the monitoring site. In addition, both rates have been decreasing with time. Belowground radiocesium occupied 90% of the total inventory in the Japanese cedar forest on October 2015. The belowground radiocesium was distributed mainly in the topsoil of 0-6 cm depth, approximately 70-80% of the underground inventory on August 2016. These results indicate that the distribution of radiocesium in the forest is similar to the distribution of tree rootlet responsible for absorption of inorganic elements, nutrients, and water. This means long residence time of radiocesium in rooting zone. In the condition of the limited amount of radiocesium input-output rates in the forest, estimation of the migration flux of radiocesium from forest floor to the forest products are considered to be most important issues in the present.

Above- and belowground distribution of radiocesium released from TEPCO' FDNPP accident in the mountainous forest of Fukushima

Niizato, Tadafumi; Sasaki, Yoshito; Ito, Satomi; Mitachi, Katsuaki*; Watanabe, Takayoshi

no journal, , 

Monitoring of radiocesium transfer on a decontaminated forest

Watanabe, Takayoshi; Sasaki, Yoshito; Niizato, Tadafumi; Mitachi, Katsuaki*; Ito, Satomi

no journal, , 

no abstracts in English

Distribution of radiocesium in Japanese cedar and Japanese konara oak forests of the Abukuma Mountains, Fukushima

Niizato, Tadafumi; Sasaki, Yoshito; Watanabe, Takayoshi; Ito, Satomi; Amamiya, Hiroki*

no journal, , 

no abstracts in English

Estimation of radiocesium uptake from forest floor in Japanese cedar and Japanese konara oak stands of the Abukuma Mountains, Fukushima

Niizato, Tadafumi; Sasaki, Yoshito; Ito, Satomi; Watanabe, Takayoshi; Amamiya, Hiroki*

no journal, , 

An understanding of long-term environmental dynamics of radiocesium in forested area, which is released by the TEPCO's Fukushima Dai-ichi Nuclear Power Plant accident, is a key issue for predicting the future forest products radioactivity. In this paper we present the radiocesium uptake from forest floor in an evergreen Japanese cedar and a deciduous Japanese konara oak forests of the Abukuma Mountains, Fukushima. An investigation was conducted from 2015 to 2019. According to the International Biological Programme, IBP, annual radiocesium uptake from forest floor to the stand is estimated as follows; annual radiocesium increment associated with tree growth plus annual loss through litterfall, stemflow, and throughfall. The rate of annual radiocesium uptake to the total inventory of the stands associated with tree growth were estimated to be 0.1 and 0.06% in Japanese konara oak and Japanese cedar stands, respectively. The sum of radiocesium uptake including the loss of radiocesium amount by litterfall, stemflow, and throughfall were 1.37 and 3.13% in the konara oak and the cedar stands, respectively. The rate of radiocesium uptake estimated are lower than the elemental uptake in deciduous tree stands near Kyoto by IBP. This indicate that the radiocesium uptake by the konara oak and the cedar stands is limited and no significant increase in radiocesium concentration of tree tissues is expected in the study stands.

FaCEIS website of radioactivity database and knowledge

Nagao, Fumiya; Kurikami, Hiroshi; Ito, Satomi; Sawada, Noriyoshi*; Oki, Noriko*

no journal, , 

JAEA is running the website named FaCEIS, in that we arrange the information about environmental radioactivity and air dose rate originated by FDNPP accident. We JAEA provide the information with scientific base to serve the knowledge and safety about Fukushima environment.