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

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

JAEA-Research 2020-007, 249 Pages, 2020/10

JAEA-Research-2020-007.pdf:15.83MB

The accident of the Fukushima Daiichi Nuclear Power Station, 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, Japan Atomic Energy Agency (JAEA) has been conducting "Long-term Assessment of Transport of Radioactive Contaminants in the Environment of Fukushima" 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.

In situ XAFS and HAXPES analysis and theoretical study of cobalt polypyrrole incorporated on carbon (CoPPyC) oxygen reduction reaction catalysts for anion-exchange membrane fuel cells

Asazawa, Koichiro*; Kishi, Hirofumi*; Tanaka, Hirohisa*; Matsumura, Daiju; Tamura, Kazuhisa; Nishihata, Yasuo; Saputro, A. G.*; Nakanishi, Hiroshi*; Kasai, Hideaki*; Artyushkova, K.*; et al.

Journal of Physical Chemistry C, 118(44), p.25480 - 25486, 2014/11

https://doi.org/10.1021/jp507534f

Operating Document on Management Division Waste Management Section in Tokai Works in the 2003 Fiscal Year

Kobayashi, Kentaro; Akutsu, Shigeru; Sasayama, Yasuo; Nakanishi, Masahiro; Ozone, Takashi; Tomomi, Terunuma,; Mogaki, Isao*

JNC TN8440 2005-007, 138 Pages, 2005/07

JNC-TN8440-2005-007.pdf:7.47MB

This document is announced about the task of Waste Management Section of Waste Management Division in 2003. Mainly, our tasks are fractionating, incinerating and storing low active solid waste and storing high active solid waste. In addition, we are performing required correspondence about management program of low level waste. We had treated and stored waste safely according to our plan. As a result, we have achieved following outcomes. 1. We incinerated the combustible low active solid waste that is generated by the operation of Tokai Reprocessing Plant and the recovery operation of incident at Low Active Liquid Waste Asphalt Solidification Facility. Waste of this recovery operation is stored in the 2nd Low Active Liquid Waste Asphalt Solidification Storage Facility. We incinerated 58 ton of wastes. 2. We stored low active solid waste 854 drums that accommodate 200L. According to the time of Low-Level Waste Treatment Facility completion, we will be able to avoid full of storage. 3. We stored high active solid waste of 148 drums that accommodate 200L. For the time being, there is no problem as regards the administration of storage facility. 4. We carried out the management program of low level solid waste according to plan.

Effects of Al composition on luminescence properties of europium implanted AlGaN(0x1)

Nakanishi, Yasuo*; Wakahara, Akihiro*; Okada, Hiroshi*; Yoshida, Akira*; Oshima, Takeshi; Ito, Hisayoshi; Shibata, Tomohiko*; Tanaka, Mitsuhiro*

Physica Status Solidi, 0(7), p.2623 - 2626, 2003/07

In our previous study, it was reported that Eu-doped Nitride semiconductors show luminescence propetires. In this study, we investigate the relationship between luminescence properties and Al composition using AlGaN(0x1). AlGaN were grown using OMVPE. Eu atoms were doped into the samples by ion implantation (200keV). After implantation, the samples were annealed to remove residual damege. Luminescence propreties of the samples were measured using photoluminescence and cathodeluminescence. As a result, luminescence at 621 nm which relates 4f-4f transition were observed for all samples (x=0 to 1). As for intensity, samples with x=0.5 show the strongest luminescence. This result can be interpreted in terms of the internal stress of crystals by the existence of Al atoms.

Effect of alloy composition on photoluminescence properties of europium implanted AlGaInN

Nakanishi, Yasuo*; Wakahara, Akihiro*; Okada, Hiroshi*; Yoshida, Akira*; Oshima, Takeshi; Ito, Hisayoshi

Physica Status Solidi (C), 0(1), p.461 - 464, 2002/12

https://doi.org/10.1002/pssc.200390088

no abstracts in English

Photoluminescence properties of Eu-doped GaN by ion implantation

Nakanishi, Yasuo*; Wakahara, Akihiro*; Yoshida, Akira*; Oshima, Takeshi; Ito, Hisayoshi; Sakai, Shiro*

IPAP Conference Series 1 (Proceedings of International Workshop on Nitride Semiconductors), p.486 - 489, 2000/11

no abstracts in English

Depositional sequence of the Post-LGM incised-valley fill controlled by seismic crustal deformation and large-scale lahars; An Example of SKM core obtained from the Sukumo coastal lowland along the Nankai Trough, Japan

Nanayama, Futoshi*; Yamaguchi, Tatsuhiko*; Nakanishi, Toshimichi; Tsuji, Tomohiro*; Ikeda, Michiharu*; Kondo, Yasuo*; Miwa, Michiko*; Sugiyama, Shinji*; Kimura, Kazunari*

no journal, , 

The characteristics of the post-LGM incised valley fills and the depositional sequence were examined the SKM core collected in the Sukumo coastal lowland, where is expected to huge seismic subsidence due to the Nankai Trough great earthquakes. Our sedimentological, radiocarbon dating and paleoenvironmental results are as bellows. Sediments of the SKM core clearly show a succession influenced by post-glacial sea level change. The Matsuda River incised valley was formed in LGM and filled by fluvial sand and gravels in late Pleistocene. After the postglacial transgression, sea level reached -30 m (a.s.l.) at 9.8 ka and the incised valley changed to an estuary environment. The sea level continued to rise and it became an inner bay mud bottom environment, and reaching a maximum water depth was at 7.5 ka. The 7.3 ka Kikai caldera eruption in southern Kyushu caused heavy K-Ah ash fall in southwestern Shikoku, and then large-scale lahars frequently occurred immediately after the ash fall because of the vicinity of volcanic source. After ash fall, the K-Ah secondary sediments rapidly deposited on the inner bay environment and caused forced regression. After 7.0 ka, the growth of the delta became active ahead of the other regions, which may be due to the large K-Ah ash fall. At 5 ka, the sea level reached + 2.5 m (a.s.l.) estimated by the Sukumo midden and this altitude is recognized as the Holocene marine limit in this area. The information on relative sea level change during the past 10000 years has revealed that the Sukumo Bay area has not subsided due to seismic crustal deformation.

Irradiation effects on rare-earth doped GaN thin films

Okada, Hiroshi*; Nakanishi, Yasuo*; Wakahara, Akihiro*; Yoshida, Akira*; Sato, Shinichiro; Oshima, Takeshi

no journal, , 

no abstracts in English