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Mo/
Tc generator by (n, 
) method, 3Fujita, Yoshitaka; Seki, Misaki; Namekawa, Yoji*; Nishikata, Kaori; Daigo, Fumihisa; Ide, Hiroshi; Tsuchiya, Kunihiko; Sano, Tadafumi*; Fujihara, Yasuyuki*; Hori, Junichi*; et al.
KURNS Progress Report 2020, P. 136, 2021/08
no abstracts in English
Mori, Kazuhiro*; Okumura, Ryo*; Yoshino, Hirofumi*; Kanayama, Masaya*; Sato, Setsuo*; Oba, Yojiro; Iwase, Kenji*; Hiraka, Haruhiro*; Hino, Masahiro*; Sano, Tadafumi*; et al.
JPS Conference Proceedings (Internet), 33, p.011093_1 - 011093_6, 2021/03
no abstracts in English
Mo-adsorption/
Tc-elution properties of alumina with different surface structuresFujita, Yoshitaka; Seki, Misaki; Sano, Tadafumi*; Fujihara, Yasuyuki*; Kitagawa, Tomoya*; Matsukura, Minoru*; Hori, Junichi*; Suzuki, Tatsuya*; Tsuchiya, Kunihiko
Journal of Radioanalytical and Nuclear Chemistry, 327(3), p.1355 - 1363, 2021/03
Times Cited Count：0 Percentile：0.01(Chemistry, Analytical)We prepared three types of Al
O
with different surface structures and investigated Mo-adsorption/Tc-elution properties using [Mo]MoO that was irradiated in the Kyoto University Research Reactor. AlO adsorbed [Mo]molybdate ions in solutions at different pH; the lower was the pH, the higher was the Mo-adsorption capacity of AlO. The Tc-elution properties of molybdate ion adsorbed AlO were elucidated by flowing saline. Consequently, it was suggested that Mo-adsorption/desorption properties are affected by the specific surface of AlO and Tc-elution properties are affected by the crystal structure of AlO.
Fukaya, Yuji; Goto, Minoru; Nakagawa, Shigeaki; Nakajima, Kunihiro*; Takahashi, Kazuki*; Sakon, Atsushi*; Sano, Tadafumi*; Hashimoto, Kengo*
EPJ Web of Conferences, 247, p.09017_1 - 09017_8, 2021/02
The Japan Atomic Energy Agency (JAEA) started the Research and Development (R&D) to improve nuclear prediction techniques for High Temperature Gas-cooled Reactors (HTGRs). The objectives are to introduce a generalized bias factor method to avoid full mock-up experiment for the first commercial HTGR and to introduce reactor noise analysis to High Temperature Engineering Test Reactor (HTTR) experiment to observe subcriticality. To achieve the objectives, the reactor core of graphite-moderation system named B7/4"G2/8"p8EUNU+3/8"p38EU(1) was newly composed in the B-rack of Kyoto University Critical Assembly (KUCA). The core is composed of the fuel assembly, driver fuel assembly, graphite reflector, and polyethylene reflector. The fuel assembly is composed of enriched uranium plate, natural uranium plate and graphite plates to realize the average fuel enrichment of HTTR and it's spectrum. However, driver fuel assembly is necessary to achieve the criticality with the small-sized core. The core plays a role of the reference core of the bias factor method, and the reactor noise was measured to develop the noise analysis scheme. In this study, the overview of the criticality experiments is reported. The reactor configuration with graphite moderation system is rare case in the KUCA experiments, and this experiment is expected to contribute not only for an HTGR development but also for other types of a reactor in the graphite moderation system such as a molten salt reactor development.
Sakon, Atsushi*; Nakajima, Kunihiro*; Takahashi, Kazuki*; Hohara, Shinya*; Sano, Tadafumi*; Fukaya, Yuji; Hashimoto, Kengo*
EPJ Web of Conferences, 247, p.09009_1 - 09009_8, 2021/02
In graphite-reflected thermal reactors, even a detector placed far from fuel region may detect a certain degree of the correlation amplitude. This is because mean free path of neutrons in graphite is longer than that in water or polyethylene. The objective of this study is experimentally to confirm a high flexibility of neutron detector placement in graphite reflector for reactor noise analysis. The present reactor noise analysis was carried out in a graphite-moderated and -reflected thermal core in Kyoto University Critical Assembly (KUCA). BF proportional neutron counters (1" dia.) were placed in graphite reflector region, where the counters were separated by about 35cm and 30cm -thick graphite from the core, respectively. At a critical state and subcritical states, time-sequence signal data from these counters were acquired and analyzed by a fast Fourier transform (FFT) analyzer, to obtain power spectral density in frequency domain. The auto-power spectral density obtained from the counters far from the core contained a significant degree of correlated component. A least-squares fit of a familiar formula to the auto-power spectral density data was made to determine the prompt-neutron decay constant. The decay constant was 63.3
14.5 [1/s] in critical state. The decay constant determined from the cross-power spectral density and coherence function data between the two counters also had a consistent value. It is confirmed that reactor noise analysis is possible using a detector placed at about 35cm far from the core, as we expected.
Seki, Misaki; Ishikawa, Koji*; Sano, Tadafumi*; Nagata, Hiroshi; Otsuka, Kaoru; Omori, Takazumi; Hanakawa, Hiroki; Ide, Hiroshi; Tsuchiya, Kunihiko; Fujihara, Yasuyuki*; et al.
KURNS Progress Report 2019, P. 279, 2020/08
no abstracts in English
Mo/Tc generator by (n,) method, 2Fujita, Yoshitaka; Seki, Misaki; Namekawa, Yoji*; Nishikata, Kaori; Kato, Yoshiaki; Sayato, Natsuki; Tsuchiya, Kunihiko; Sano, Tadafumi*; Fujihara, Yasuyuki*; Hori, Junichi*; et al.
KURNS Progress Report 2019, P. 157, 2020/08
no abstracts in English
Fukaya, Yuji; Goto, Minoru; Nakagawa, Shigeaki; Nakajima, Kunihiro*; Takahashi, Kazuki*; Sakon, Atsushi*; Sano, Tadafumi*; Hashimoto, Kengo*
Proceedings of International Conference on the Physics of Reactors; Transition To A Scalable Nuclear Future (PHYSOR 2020) (USB Flash Drive), 8 Pages, 2020/03
The Japan Atomic Energy Agency (JAEA) started the Research and Development (R&D) to improve nuclear prediction techniques for High Temperature Gas-cooled Reactors (HTGRs). The objectives are to introduce a generalized bias factor method to avoid full mock-up experiment for the first commercial HTGR and to introduce reactor noise analysis to High Temperature Engineering Test Reactor (HTTR) experiment to observe subcriticality. To achieve the objectives, the reactor core of graphite-moderation system named B7/4"G2/8"p8EUNU+3/8"p38EU(1) was newly composed in the B-rack of Kyoto University Critical Assembly (KUCA). The core is composed of the fuel assembly, driver fuel assembly, graphite reflector, and polyethylene reflector. The fuel assembly is composed of enriched uranium plate, natural uranium plate and graphite plates to realize the average fuel enrichment of HTTR and it's spectrum. However, driver fuel assembly is necessary to achieve the criticality with the small-sized core. The core plays a role of the reference core of the bias factor method, and the reactor noise was measured to develop the noise analysis scheme. In this study, the overview of the criticality experiments is reported. The reactor configuration with graphite moderation system is rare case in the KUCA experiments, and this experiment is expected to contribute not only for an HTGR development but also for other types of a reactor in the graphite moderation system such as a molten salt reactor development.
Seki, Misaki; Ishikawa, Koji*; Nagata, Hiroshi; Otsuka, Kaoru; Omori, Takazumi; Hanakawa, Hiroki; Ide, Hiroshi; Tsuchiya, Kunihiko; Sano, Tadafumi*; Fujihara, Yasuyuki*; et al.
KURNS Progress Report 2018, P. 257, 2019/08
no abstracts in English
Fukaya, Yuji; Nakagawa, Shigeaki; Goto, Minoru; Ishitsuka, Etsuo; Kawakami, Satoru; Uesaka, Takahiro; Morita, Keisuke; Sano, Tadafumi*
KURNS Progress Report 2018, P. 148, 2019/08
The Japan Atomic Energy Agency (JAEA) started the Research and Development (R&D) to improve nuclear prediction techniques for High Temperature Gas-cooled Reactors (HTGRs). The objectives are to introduce generalized bias factor method to avoid full mock-up experiment for the first commercial HTGR and to introduce reactor noise analysis to High Temperature Engineering Test Reactor (HTTR) experiment. To achieve the objectives, the reactor core of graphite moderation system named B7/4"G2/8"p8EUNU+3/8"p38EU(1) was newly composed in the B-rack of Kyoto University Critical Assembly (KUCA). The core plays a role of the reference core of the bias factor method, and the reactor noise was measured to develop the noise analysis scheme. In addition, training of operator of HTTR was also performed during the experiments.
Oizumi, Akito; Fukushima, Masahiro; Tsujimoto, Kazufumi; Chiba, Go*; Yamanaka, Masao*; Sano, Tadafumi*; Pyeon, C. H.*
KURNS Progress Report 2018, P. 38, 2019/08
In the nuclear transmutation system such as ADS, the nuclear data validation of MA is required to reduce the uncertainty caused by the nuclear data of MA. This study aims to measure the fission reaction rate ratios (FRRs) of Neptunium-237 (
Np) or Americium-241 (
Am) to Uranium-235 (
U) by using a back-to-back (BTB) fission chamber in the KUCA built as a sub-critical core (k
= 0.998) with the nuclear spallation neutron source. The result showed that the measured FRRs of Np/U and Am/U were 0.014 0.002 and 0.023 0.005, respectively. These measured values will be used for verification of evaluated nuclear data by conducting detailed analyses.
Mo/Tc generator by (n,) methodFujita, Yoshitaka; Seki, Misaki; Namekawa, Yoji*; Nishikata, Kaori; Kimura, Akihiro; Shibata, Akira; Sayato, Natsuki; Tsuchiya, Kunihiko; Sano, Tadafumi*; Fujihara, Yasuyuki*; et al.
KURNS Progress Report 2018, P. 155, 2019/08
no abstracts in English
Am neutron capture and total cross sections with ANNRI at J-PARCKimura, Atsushi; Nakamura, Shoji; Terada, Kazushi*; Nakao, Taro*; Mizuyama, Kazuhito*; Iwamoto, Nobuyuki; Iwamoto, Osamu; Harada, Hideo; Katabuchi, Tatsuya*; Igashira, Masayuki*; et al.
Journal of Nuclear Science and Technology, 56(6), p.479 - 492, 2019/06
Times Cited Count：5 Percentile：75.46(Nuclear Science & Technology)Am with ANNRI at J-PARCTerada, Kazushi*; Kimura, Atsushi; Nakao, Taro*; Nakamura, Shoji; Mizuyama, Kazuhito*; Iwamoto, Nobuyuki; Iwamoto, Osamu; Harada, Hideo; Katabuchi, Tatsuya*; Igashira, Masayuki*; et al.
Journal of Nuclear Science and Technology, 55(10), p.1198 - 1211, 2018/10
Times Cited Count：10 Percentile：87.34(Nuclear Science & Technology)Kitatani, Fumito; Tsuchiya, Harufumi; Toh, Yosuke; Hori, Junichi*; Sano, Tadafumi*; Takahashi, Yoshiyuki*; Nakajima, Ken*
KURRI Progress Report 2017, P. 99, 2018/08
Oizumi, Akito; Fukushima, Masahiro; Tsujimoto, Kazufumi; Yamanaka, Masao*; Sano, Tadafumi*; Pyeon, C. H.*
KURRI Progress Report 2017, P. 50, 2018/08
In the nuclear transmutation system such as ADS, the nuclear data validation of MA is required to reduce the uncertainty caused by the nuclear data of MA. This study aims to measure the reaction rates of Neptunium-237 (Np) and Americium-241 (Am) using the nuclear spallation neutron source in the KUCA for 3 hours. The observed distributions of pulse-height of Np and Am fission reactions were significantly different from the ones generally observed in critical and pulsed neutron source (PNS) experiments because of the influence of the -ray generated by the nuclear spallation reaction. On the other hand, the capture reaction rate of Np was measured in this experiment. The capture reaction rate of the critical experiment which was available to be measured the fission reaction rate of Np and Am was almost 8 times larger than that of this experiment. Consequently, reducing the influence of the generated by the nuclear spallation reaction and extending the duration of the irradiation to 24 or more hours would be necessary for detecting signals of fission reactions under the spallation neutron source.
pellets for Mo-99 productionFujita, Yoshitaka; Nishikata, Kaori; Namekawa, Yoji*; Kimura, Akihiro; Shibata, Akira; Sayato, Natsuki; Tsuchiya, Kunihiko; Sano, Tadafumi*; Fujihara, Yasuyuki*; Zhang, J.*
KURRI Progress Report 2017, P. 126, 2018/08
no abstracts in English
Am reactor activation measurements
erovnik, G.*; Schillebeeckx, P.*; Becker, B.*; Fiorito, L.*; Harada, Hideo; Kopecky, S.*; Radulovic, V.*; Sano, Tadafumi*
Nuclear Instruments and Methods in Physics Research A, 877, p.300 - 313, 2018/01
Times Cited Count：3 Percentile：45.99(Instruments & Instrumentation)Methodologies to derive cross section data from spectrum integrated reaction rates were studied. The Westcott convention and some of its approximations were considered. The accuracy of the results strongly depends on the assumptions that are made about the neutron energy distribution, which is mostly parameterised as a sum of a thermal and an epi-thermal component. Resonance integrals derived from such data can be strongly biased. When the energy dependence of the cross section is known and information about the neutron energy distribution is available, a method to correct for a bias on the cross section at thermal energy is proposed. Reactor activation measurements to determine the thermal Am(n, ) cross section reported in the literature were reviewed, where the results were corrected to account for possible biases. These data combined with results of time-of-flight measurements give a capture cross section 720 (14) b for Am(n, ) at thermal energy.
Harada, Hideo; Iwamoto, Osamu; Iwamoto, Nobuyuki; Kimura, Atsushi; Terada, Kazushi; Nakao, Taro; Nakamura, Shoji; Mizuyama, Kazuhito; Igashira, Masayuki*; Katabuchi, Tatsuya*; et al.
EPJ Web of Conferences, 146, p.11001_1 - 11001_6, 2017/09
Times Cited Count：2 Percentile：85.61 Am and Np capture cross sectionserovnik, G.*; Schillebeeckx, P.*; Cano-Ott, D.*; Jandel, M.*; Hori, Junichi*; Kimura, Atsushi; Rossbach, M.*; Letourneau, A.*; Noguere, G.*; Leconte, P.*; et al.
EPJ Web of Conferences, 146, p.11035_1 - 11035_4, 2017/09
Times Cited Count：4 Percentile：95.35