Bioaccessibility of Fukushima-accident-derived Cs in soils and the contribution of soil ingestion to radiation doses in children

Takahara, Shogo; Ikegami, Maiko*; Yoneda, Minoru*; Kondo, Hitoshi*; Ishizaki, Azusa; Iijima, Masashi; Shimada, Yoko*; Matsui, Yasuto*

Risk Analysis, 37(7), p.1256 - 1267, 2017/07

AA2015-0445.pdf:0.53MB

https://doi.org/10.1111/risa.12694

Radiation monitoring using the unmanned helicopter after the accident of the nuclear power plant

Sanada, Yukihisa; Nishizawa, Yukiyasu; Yamada, Tsutomu; Ikeda, Kazutaka*; Matsui, Masashi*; Tsuchida, Kiyofumi; Sato, Yoshiharu; Hirayama, Hirokatsu; Takamura, Yoshihide; Nishihara, Katsuya; et al.

JAEA-Research 2013-049, 129 Pages, 2014/03

JAEA-Research-2013-049.pdf:15.5MB

By the nuclear disaster of Fukushima Daiichi Nuclear Power Plant (NPP), Tokyo Electric Power Company (TEPCO), caused by the East Japan earthquake and the following tsunami occurred on March 11, 2011, a large amount of radioactive materials was released from the NPP. In recent years, technologies for autonomous unmanned helicopters (AUHs) have been developed and applied to natural disasters. In expectation of the application of the AUHs to aerial radiation monitoring, we had developed a remote radiation monitoring system. Then, we measured the radiation level by using unmanned helicopter in soil contaminated areas by radioactive cesium emitted from the NPP to evaluate ambient dose-rate distribution around the areas and to investigate the decontamination effect by the measurements before and after decontamination treatment. Here, we reports on the measurement technique and the result.

MFM and PEEM observation of micrometre-sized magnetic dot arrays fabricated by ion-microbeam irradiation in FeRh thin films

Aiko, Kazuma*; Toki, Atsushi*; Matsui, Toshiyuki*; Iwase, Akihiro*; Sato, Takahiro; Takano, Katsuyoshi*; Koka, Masashi; Saito, Yuichi; Kamiya, Tomihiro; Okochi, Takuo*; et al.

Journal of Synchrotron Radiation, 19(2), p.223 - 226, 2012/03

https://doi.org/10.1107/S0909049511054057

Countermeasures planned for reducing water inflow into deep shafts at the Mizunami Underground Research Laboratory (Research for post-excavation grouting)

Kuji, Masayoshi*; Matsui, Hiroya; Hara, Masato; Minamide, Masashi*; Mikake, Shinichiro; Takeuchi, Shinji; Sato, Toshinori*; Asai, Hideaki

JAEA-Research 2008-095, 54 Pages, 2009/01

JAEA-Research-2008-095.pdf:13.14MB

A large amount of water inflow is frequently generated during the excavation of an underground cavern, such as road and railway tunnels, underground electric facilities etc. The reduction of water inflow is sometimes quite important for the reduction of cost for the water treatment and pumping during the construction of an underground cavern. The Mizunami Underground Research Laboratory (MIU) is currently being constructed by Japan Atomic Energy Agency. During its excavation, a large amount of water inflow into the shafts has been increasing and affecting the project progress. Therefore, a field experiment of post-excavation grouting around the Ventilation Shaft in a sedimentary formation carried out to confirm the effect of existing grouting technology for sedimentary formations in MIU project. The result shows that the applied methods in this field experiment are effective to prevent water inflow. This report describes the summary of the field experiment and the knowledge obtained through the experiment.

Horonobe Underground Research Laboratory Project; Investigation report for the 2006 fiscal year

Matsui, Hiroya; Nakayama, Masashi; Sanada, Hiroyuki

JAEA-Research 2007-092, 83 Pages, 2008/05

JAEA-Research-2007-092.pdf:16.75MB

The Horonobe URL project is planned to extend over a period of 20 years. The investigations will be conducted in three phases, namely Surface-based investigations, Construction Phase (investigations during construction of the underground facilities) and Operation phase (research in the underground facilities). This report summerizes the results of the investigations for 2006 fiscal year (2006/2007), the second year of the Phase 2 investigations. The investigations, which are composed of Geoscientific research and R&D on geological disposal of high-level radioactive waste (HLW), were carried out according to Horonobe Underground Research Laboratory Project Investigation Program for the 2006 Fiscal Year.

Horonobe Underground Research Laboratory project investigation program for the 2007 fiscal year

Matsui, Hiroya; Nakayama, Masashi; Sanada, Hiroyuki; Yamaguchi, Takehiro

JAEA-Research 2007-048, 36 Pages, 2007/07

JAEA-Research-2007-048.pdf:13.4MB

As part of the research and development program on geological disposal of HLW, the Horonobe Underground Research Center, a division of the JAEA is implementing the Horonobe URL Project with the aim of investigating sedimentary rock formations. The Horonobe URL Project is planned to extend over a period of 20 years. The investigations will be conducted in three phases. In the 2007 fiscal year, investigations in Geoscientific Research is continuously carried out. Investigations in R&D on Geological Disposal Technology is also continuously carried out. Construction of the underground facilities is ongoing at Ventilation Shaft and Access Shaft (East). Pre-boring around Ventilation Shaft is also carried out. Construction of the Public Information House and preparation of the exhibits are still continuing and will be completed in May 2007. Public Information House will be scheduled to open in summer. An execution design will be drawn up for the International Communication House.

The Study plan on applicability to actual geological environment conditions of the engineering technology for geological disposal of high level nuclear-waste through the second phases in Horonobe Underground Research Project

Aoyanagi, Shigeo; Yui, Mikazu; Tanai, Kenji; Kawakami, Susumu; Fujita, Tomoo; Taniguchi, Naoki; Shibata, Masahiro; Konishi, Kazuhiro; Nishimura, Mayuka; Kikuchi, Hirohito*; et al.

JAEA-Review 2006-014, 61 Pages, 2006/03

JAEA-Review-2006-014.pdf:5.03MB

no abstracts in English

Out-pile tests for improved type rabbits in JMTR

Kitagishi, Shigeru; Isozaki, Futoshi; Takita, Kenji; Aoyama, Masashi; Matsui, Yoshinori

no journal, , 

As one of the production of radioisotopes, JMTR has a plan to produce Mo which is a parent nuclide of Tc. The new hydraulic-rabbit-irradiation-facility is carried out to be set up in the preparation of the Mo production facility. For the expansion of use, the new facility was designed to be able to irradiate rabbits more than it used to be. However, it takes more than about ten days to assemble the rabbit. For this reason, it is required shortening of the assembly period. The improved type of rabbit, which was developed to shorten the assembly period in JRR-3, was focused. And, out-pile tests were carried out for research of the fabrication of the improved type rabbit and the endurance performance under the usage environment in JMTR. In these tests, first, the assembly device for the improved type of rabbit was designed and fabricated, and the fabrication test was carried out using the assembly device. Next, the endurance performance tests were carried out using mock-up rabbits. From the results of these tests, there were bright prospects of the manufacturability of the improved type of rabbit had good sealing performance and utilizing in the irradiation test of JMTR.