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JAEA Reports

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.

Journal Articles

Cryogenic sample environments shared at the MLF, J-PARC

Kawamura, Seiko; Takahashi, Ryuta*; Ishikado, Motoyuki*; Yamauchi, Yasuhiro*; Nakamura, Masatoshi*; Ouchi, Keiichi*; Kira, Hiroshi*; Kambara, Wataru*; Aoyama, Kazuhiro*; Sakaguchi, Yoshifumi*; et al.

Journal of Neutron Research, 21(1-2), p.17 - 22, 2019/05

The Cryogenics and Magnets group in the Sample Environment team is responsible for operation of cryostats and magnets for user's experiments at the MLF in J-PARC. We have introduced a top-loading $$^4$$He cryostat, a bottom-loading $$^3$$He cryostat, a dilution refrigerator insert and a superconducting magnet. The frequency of use of them dramatically becomes higher in these two years, as the beam power and the number of proposal increase. To respond such situation, we have made efforts to enhance performance of these equipment as follows. The $$^3$$He cryostat originally involves an operation software for automatic initial cooling down to the base temperature and automatic re-charge of $$^3$$He. Recently we made an additional program for automatic temperature control with only the sorb heater. Last year, a new outer vacuum chamber of the magnet with an oscillating radial collimator (ORC) was fabricated. The data quality was drastically improved by introducing this ORC so that the magnet can be used even for the inelastic neutron scattering experiments.

Journal Articles

Estimation of the release time of radio-tellurium during the Fukushima Daiichi Nuclear Power Plant accident and its relationship to individual plant events

Takahashi, Sentaro*; Kawashima, Shigeto*; Hidaka, Akihide; Tanaka, Sota*; Takahashi, Tomoyuki*

Nuclear Technology, 205(5), p.646 - 654, 2019/05

Journal Articles

7.2.3 Towards implementation of Fukushima environmental remediation

Miyahara, Kaname; Kawase, Keiichi

Genshiryoku No Ima To Ashita, p.159 - 167, 2019/03

This manuscript overviews lessons learned from decontamination pilot projects towards implementation of regional remediation after the environmental contamination due to the Fukushima Daiichi Nuclear Power Plant Accidents.

JAEA Reports

Progress report on Nuclear Safety Research Center; JFY 2015 - 2017

Nuclear Safety Research Center, Sector of Nuclear Safety Research and Emergency Preparedness

JAEA-Review 2018-022, 201 Pages, 2019/01

JAEA-Review-2018-022.pdf:20.61MB

Nuclear Safety Research Center (NSRC), Sector of Nuclear Safety Research and Emergency Preparedness, Japan Atomic Energy Agency (JAEA) is conducting technical support to nuclear safety regulation and safety research based on the Mid-Long Term Target determined by Japanese government. This report summarizes the research structure of NSRC and the cooperative research activities with domestic and international organizations as well as the nuclear safety research activities and results in the period from JFY 2015 to 2017 on the nine research fields in NSRC; (1) severe accident analysis, (2) radiation risk analysis, (3) safety of nuclear fuels in light water reactors (LWRs), (4) thermohydraulic behavior under severe accident in LWRs, (5) materials degradation and structural integrity, (6) safety of nuclear fuel cycle facilities, (7) safety management on criticality, (8) safety of radioactive waste management, and (9) nuclear safeguards.

Journal Articles

Estimation of environmental releases of radioactive materials

Chino, Masamichi*; Nagai, Haruyasu

Environmental Contamination from the Fukushima Nuclear Disaster; Dispersion, Monitoring, Mitigation and Lessons Learned, p.50 - 61, 2019/00

Temporal variations in the amount of radionuclides released into the atmosphere during the Fukushima Daiichi Nuclear Power Station accident and their atmospheric dispersion are essential to evaluate the environmental impacts and resultant radiological doses to the public. We have estimated the atmospheric releases during the accident by comparing measurements with calculations by atmospheric deposition model. UNSCEAR compared several estimated source terms and used our source term for estimating levels of radioactive material in the terrestrial environment and doses to the public. To improve our source term, we recently made detailed source term estimation by using additional monitoring data and WSPEEDI including new deposition scheme.

Journal Articles

Modelling the effect of mechanical remediation on dose rates above radiocesium contaminated land

Malins, A.; Kurikami, Hiroshi; Kitamura, Akihiro; Machida, Masahiko

Remediation Measures for Radioactively Contaminated Areas, p.259 - 272, 2019/00

Journal Articles

Activities for environmental restoration in Fukushima Environmental Safety Center of JAEA; Miharu-town and Minamisoma-city

Shobu, Nobuhiro

Enerugi Rebyu, 37(10), p.21 - 22, 2017/10

After the Fukushima-Daiichi Nuclear Power Plant Accident, Japan Atomic Energy Agency (JAEA) has been carrying out research and development activities towards the environmental restoration of Fukushima. This paper describes the following representative activities in Fukushima Environmental Safety Center of JAEA, such as the development of environmental monitoring and mapping technologies, the long-term assessment of transport of radio-cesium in the environment of Fukushima, and the technology development for advancing decontamination and volume reduction technologies.

Journal Articles

Towards enhancing Fukushima environmental resilience

Miyahara, Kaname

Transactions of the American Nuclear Society, 117(1), p.51 - 52, 2017/10

This presentation highlights JAEA's challenges for contributing to recovering the previous life of residents and the development of resilient communities in Fukushima Prefecture based on considering needs of local people on the environmental restoration categorized by the state of evacuation orders and the lifting of such orders.

Journal Articles

Release behavior of Cs and its chemical form during late phase of Fukushima Daiichi Nuclear Power Plant accident

Hidaka, Akihide; Yokoyama, Hiroya

Proceedings of Symposium on Water Chemistry and Corrosion in Nuclear Power Plants in Asia 2017 (AWC 2017) (USB Flash Drive), p.29 - 42, 2017/09

no abstracts in English

Journal Articles

Challenges for enhancing Fukushima environmental resilience, 1; Status and lessons

Miyahara, Kaname; Ohara, Toshimasa*

Nippon Genshiryoku Gakkai-Shi, 59(5), p.282 - 286, 2017/05

This review highlights JAEA and NIES's challenges for enhancing Fukushima environmental resilience based on carrying out multifaceted research working with many public and private sector organizations and academia.

Journal Articles

An Overview of progress in environmental research on radioactive materials derived from the Fukushima Nuclear accident

Ohara, Toshimasa*; Miyahara, Kaname

Global Environmental Research (Internet), 20(1&2), p.3 - 13, 2017/03

Toward the environmental regeneration in Fukushima Prefecture and other areas after the Fukushima Daiichi Nuclear Power Station accidents, JAEA and NIES working with many public and private sector organizations and academia have carried out multifaceted research that will help to restore the environment of affected areas. These challenging efforts need to be further strengthened.

Journal Articles

Prospects for researches on environmental and health effects of the Fukushima Dai-ichi NPP accident

Hirouchi, Jun; Okura, Takehisa; Satoh, Daiki

Nippon Genshiryoku Gakkai-Shi, 59(3), p.152 - 155, 2017/03

no abstracts in English

Journal Articles

Utilization of $$^{134}$$Cs/$$^{137}$$Cs in the environment to identify the reactor units that caused atmospheric releases during the Fukushima Daiichi accident

Chino, Masamichi; Terada, Hiroaki; Nagai, Haruyasu; Katata, Genki; Mikami, Satoshi; Torii, Tatsuo; Saito, Kimiaki; Nishizawa, Yukiyasu

Scientific Reports (Internet), 6, p.31376_1 - 31376_14, 2016/08

 Times Cited Count:10 Percentile:8.68(Multidisciplinary Sciences)

JAEA Reports

Project report on the construction phase at the Mizunami Underground Research Laboratory Project

Nohara, Tsuyoshi; Saegusa, Hiromitsu*; Iwatsuki, Teruki; Hama, Katsuhiro; Matsui, Hiroya; Mikake, Shinichiro; Takeuchi, Ryuji; Onoe, Hironori; Sasao, Eiji

JAEA-Research 2015-026, 98 Pages, 2016/03

JAEA-Research-2015-026.pdf:32.97MB

Tono Geoscience Center (TGC) of Japan Atomic Energy Agency (JAEA) is being performed Mizunami Underground Research Laboratory (MIU) Project, which is a broad scientific study of the deep geological environment as a basis of research and development for geological disposal of nuclear wastes, in order to establish comprehensive techniques for the investigation, analysis and assessment of the deep geological environment in fractured crystalline rock. The MIU Project has three overlapping phases: Surface-based Investigation phase (Phase I), Construction phase (Phase II), and Operation phase (Phase III). The project goals of the MIU Project from Phase I through to Phase III are: (1) to establish techniques for investigation, analysis and assessment of the deep geological environment, and (2) to develop a range of engineering for deep underground application. This report summarizes the results of geoscientific study on Phase II to 500m depth. During Construction phase, we have evaluated of adequacy of techniques for investigation, analysis and assessment of the deep geological environment on Surface-based Investigation phase, and have established systematic methodology for stepwise investigation and evaluation of the geological environment on Construction phase. Further, with respect to design and construction of underground facilities, it was confirmed the validity of the engineering involved in the construction, maintenance and management of underground facilities.

JAEA Reports

Study on innovative HTGR to reduce generation of potential radiotoxicity

Fukaya, Yuji; Goto, Minoru; Nishihara, Tetsuo

JAEA-Research 2015-023, 44 Pages, 2016/02

JAEA-Research-2015-023.pdf:2.13MB

A study on innovative High Temperature Gas-cooled Reactor (HTGR) to reduce generation of potential radiotoxicity had been performed. Unlike the Fast Breeder Reactor (FBR) and Accelerated Driven System (ADS), which can confine radioactive nuclides into its fuel cycle as multi-recycling and transmute, in this study we attempt to reduce the generation of the radiotoxicity itself by preventing the generation of Pu and MA, which is generated with the energy generation. In this context, we proposed the innovative HTGR that employs the Highly Enriched Uranium (HEU) fuel by removing $$^{238}$$U : source of the Pu and MA. However, there are the problems of fuel integrity, nuclear proliferation, nuclear self-regulation characteristics, and economy of electricity generation which are caused by employing HEU. For these problems, we investigated and proposed the solutions. Especially for the nuclear self-regulation characteristics, which were improved by adding Er, the optimized nuclear design was quantitatively determined and elucidated by the Bondarenko approach. As a result, it was confirmed that the proposed reactor can solves these problem for employing HEU fuel and the high specification and economy as same as those of standard HTGR fueled uranium.

Journal Articles

Synthesis of sodium dodecyl sulfate-supported nanocomposite cation exchanger; Removal and recovery of Cu$$^{2+}$$ from synthetic, pharmaceutical and alloy samples

Naushad, M.*; Alothman, Z. A.*; Alam, M. M.*; Awual, M. R.; Eldesoky, G. E.*; Islam, M.*

Journal of the Iranian Chemical Society, 12(9), p.1677 - 1686, 2015/09

 Times Cited Count:21 Percentile:23.44(Chemistry, Multidisciplinary)

Journal Articles

Modeling approach to various time and spatial scale environmental issues in Fukushima; Related to radioactive cesium migration in aquatic systems

Kurikami, Hiroshi; Kitamura, Akihiro; Yamada, Susumu; Machida, Masahiko

Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM), 6 Pages, 2015/05

Several numerical models have been prepared to deal with various time- and spatial-scale issues related to radioactive cesium migration in environment in Fukushima area. This paper describes fragments of the JAEA's approaches of modeling to deal with the issues corresponding to radioactive cesium migration in environment with some case studies.

Journal Articles

Colorimetric detection and removal of copper(II) ions from wastewater samples using tailor-made composite adsorbent

Awual, M. R.; Hasan, M. M.*

Sensors and Actuators B; Chemical, 206, p.692 - 700, 2015/01

 Times Cited Count:83 Percentile:0.57(Chemistry, Analytical)

Journal Articles

Measurements and evaluations of air dose rates around Fukushima, 3; Characteristics of environmental $$gamma$$ rays and the exposure doses

Saito, Kimiaki; Endo, Akira

Radioisotopes, 63(12), p.585 - 602, 2014/12

The article provides the fundamental information necessary for the appropriate evaluation of exposure doses in the environment. The basic characteristics of environmental $$gamma$$ rays from typical environmental sources are introduced; then, the dose conversion coeffcients for the public at different ages are summarized which were obtained from the simulation considering the basic characteristics of environmental $$gamma$$ rays. Further, the variations of environmental exposure doses due to a variety of factors, and the relation of exposure doses to measured air dose rates are discussed.

168 (Records 1-20 displayed on this page)