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Zaima, Naoki; Nakatsuka, Yoshiaki; Fujiki, Naoki*; Nakashima, Shinichi; Yoshida, Hideaki; Kureta, Masatoshi; Ozu, Akira; Komeda, Masao; Takase, Misao; Haruyama, Mitsuo
no journal, ,
We have just started to develop the uranium mass assay system for 200-litter wastes drums applied active neutron measurements by Non-Destructive Assay (NDA) method composed of the neutron generator used small ultra accelerator and neutron detectors. This system is the extension of the passive neutron system which we had been developed previously, is to be expected to purchase the uranium determination for the actual uranium wastes and to prepare fine data of safe guards. The configurations are that (d,T) accelerator, Helium-3 proportional counters, and 50 cm of concrete structure as reflector and shielding. The uranium mass are determined by counting secondary neutrons generated from nuclear fissions induced from 14 MeV accelerator neutrons. Several mockup wastes drums used the uranium sources had been carried out and reached a conviction of the availability of this methodology.
Okamoto, Tsutomu; Okumura, Keisuke
no journal, ,
In a long-term environmental impact assessment, it is important to evaluate the amount of radioactive carbon (C-14) emitted at the accident of the Tokyo Electric Power Company, Incorporated Fukushima Daiichi Nuclear Power Station. C-14 is mainly produced from radio-activation of impurities in the fuel, cladding, etc. In the present study, the inventory of C-14 accumulated in each core of unit 1 to 3 until just before the accident is estimated by the activation calculation with the latest nuclear data, in order to contribute to the source term evaluation and long-term environmental impact assessment in future.
Takamine, Jun; Harada, Hideo; Kureta, Masatoshi; Koizumi, Mitsuo; Kitatani, Fumito; Tsuchiya, Harufumi; Iimura, Hideki; Kimura, Atsushi
no journal, ,
Neutron resonance densitometry (NRD) has been proposed to quantify nuclearmaterials in melted fuel that will be removed from the Fukushima Daiichi Nuclear Power Plant. NRD is based on a combination of neutron resonancetransmission analysis (NRTA) and neutron resonance capture analysis. The major performance of NRTA system using a pulsed neutron source, such as S/N ratio and energy resolution, is determined by the flight distance and pulse width of the neutron source mainly. In this study, using a Monte Carlo simulation code, the NRTA of uranium and plutonium isotopes was simulated. the influence of quantitative accuracy of uranium and plutonium isotopes was evaluated with changing the flight distance and the pulse width.
Ozu, Akira; Takase, Misao; Kurata, Noritaka; Kobayashi, Nozomi; Yoshino, Seiji; Kureta, Masatoshi; Nakamura, Tatsuya; Soyama, Kazuhiko; Nakamura, Hironobu; Seya, Michio; et al.
no journal, ,
no abstracts in English
Nakatsuka, Yoshiaki; Zaima, Naoki; Fujiki, Naoki*; Nakashima, Shinichi; Yoshida, Hideaki; Kureta, Masatoshi; Ozu, Akira; Komeda, Masao; Takase, Misao; Haruyama, Mitsuo
no journal, ,
We have just started to operate the extremely small accelerator for the purpose of the neutron assay against the uranium bearing wastes drums, so called active assay of NDA, which is an extension of the passive assay system, NWAS at Ningyo-toge Environmental Technical Center. The purposes of both are the improvements for measurements methodology and the accuracy of safe-guards data by determining uranium mass. The systems are composed of the (d,T) accelerator as a generator of 14 MeV neutrons, and Helium-3 proportional counters which detect the neutrons derived from U-235 fissions. Uranium mass are to be determined through detecting and analyzing fission neutrons, FNDI (Fast Neutron Direct Interrogation) method, which had been developed by the Nuclear Science and Engineering Directorate of JAEA. After configuration systems we had carried out the basic tests, and had validated the high sensitivity neutron detection and high precision determination.
Tada, Kenichi; Nagaya, Yasunobu
no journal, ,
no abstracts in English
Tsuchiya, Harufumi; Harada, Hideo; Koizumi, Mitsuo; Kitatani, Fumito; Takamine, Jun; Kureta, Masatoshi; Iimura, Hideki
no journal, ,
no abstracts in English
Haruyama, Mitsuo; Ozu, Akira; Takase, Misao; Komeda, Masao; Kureta, Masatoshi
no journal, ,
no abstracts in English
Zaima, Naoki; Nakatsuka, Yoshiaki; Fujiki, Naoki*; Nakashima, Shinichi; Yoshida, Hideaki; Kureta, Masatoshi; Ozu, Akira; Komeda, Masao; Takase, Misao; Haruyama, Mitsuo
no journal, ,
We have just started to operate the extremely small accelerator for the purpose of the neutron assay against the uranium bearing wastes drums, so called active assay of NDA, which is an extension of the passive assay system, NWAS at Ningyo-toge Environmental Technical Center. The purposes of both are the improvements for measurements methodology and the accuracy of safe-guards data by determining uranium mass. The systems are composed of the (d,T) accelerator as a generator of 14 MeV neutrons, and Helium-3 proportional counters which detect the neutrons derived from U-235 fissions. Uranium mass are to be determined through detecting and analyzing fission neutrons, FNDI (Fast Neutron Direct Interrogation) method, which had been developed by the Nuclear Science and Engineering Directorate of JAEA. After configuration systems we had carried out the basic tests, and had validated the high sensitivity neutron detection and high precision determination.
Komeda, Masao; Ozu, Akira; Haruyama, Mitsuo; Takase, Misao; Kureta, Masatoshi; Nakatsuka, Yoshiaki; Zaima, Naoki; Nakashima, Shinichi
no journal, ,
no abstracts in English
Arai, Yusuke*; Honda, Teruyuki*; Iwatsuki, Teruki; Nomura, Masao*
no journal, ,
The occurrence of rare earth elements in alteration rock and fault of Toki granite was observed to infer the migration process of minor actinides. The light rare earth elements concentrated in alteration rock and fault compared to fresh rock due to precipitation as a secondary mineral and adsorption onto clay minerals. This suggests the possibility of retardation of minor actinides by alteration minerals.
Sakasai, Kaoru; Nakamura, Tatsuya; To, Kentaro; Suzuki, Hiroyuki; Ozu, Akira; Ebine, Masumi; Birumachi, Atsushi; Takase, Misao; Kurata, Noritaka; Yoshino, Seiji; et al.
no journal, ,
We have developed the neutron-sensitive scintillator neutron counter for nuclear safeguards. The detector is made based on the scintillator detector technology developed long in the J-PARC/MLF. The detector is comprised of the ZnS/B
O
ceramic scintillator, rectangular shaped light guide and photomultiplier tubes. The detector performances including detector efficiency and its incident position dependence and 
-ray sensitivity are presented in detail.
Birumachi, Atsushi; Ebine, Masumi; Nakamura, Tatsuya; To, Kentaro; Sakasai, Kaoru; Honda, Katsunori; Soyama, Kazuhiko; Katagiri, Masaki*
no journal, ,
no abstracts in English
Ebine, Masumi; Birumachi, Atsushi; Nakamura, Tatsuya; To, Kentaro; Sakasai, Kaoru; Honda, Katsunori; Soyama, Kazuhiko; Katagiri, Masaki*
no journal, ,
no abstracts in English
Nakamura, Tatsuya; To, Kentaro; Sakasai, Kaoru; Honda, Katsunori; Ebine, Masumi; Birumachi, Atsushi; Soyama, Kazuhiko; Katagiri, Masaki*
no journal, ,
We have initiated the development of the two-dimensional scintillator neutron detector for a protein diffractometer. The diffractometer is planned to be built in the J-PARC/MLF near future. We propose the detector designs that could fulfill the required specification for the instrument together with some basic experimental results.
Yoshida, Hiroyuki; Nagatake, Taku; Takase, Kazuyuki; Kaneko, Akiko*; Monji, Hideaki*; Abe, Yutaka*
no journal, ,
no abstracts in English
Akie, Hiroshi; Nakano, Yoshihiro; Nishihara, Kenji; Iwamura, Takamichi*; Shirasu, Noriko
no journal, ,
no abstracts in English
Nakajima, Motoki; Hirose, Takanori; Tanigawa, Hisashi; Tanigawa, Hiroyasu; Enoeda, Mikio
no journal, ,
no abstracts in English
Horiguchi, Naoki; Yoshida, Hiroyuki; Kaneko, Akiko*; Abe, Yutaka*
no journal, ,
no abstracts in English
Ito, Yuzuru; Terai, Takayuki*; Suzuki, Akihiro*; Fukada, Satoshi*; Yagi, Juro*; Watanabe, Kazuyoshi; Kondo, Hiroo; Furukawa, Tomohiro; Wakai, Eiichi
no journal, ,
no abstracts in English