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Pyeon, C. H.*; Yamanaka, Masao*; Fukushima, Masahiro
Nuclear Science and Engineering, 195(8), p.877 - 889, 2021/08
Times Cited Count：5 Percentile：64.12(Nuclear Science & Technology)Uncertainty quantification of lead (Pb) and bismuth (Bi) sample reactivity worth is numerically determined using the SCALE6.2 code system and experimental results obtained from the solid-moderated and solid-reflected core at the Kyoto University Critical Assembly (KUCA) to demonstrate the sensitivity coefficients of aluminum (Al) and Bi scattering reactions. From the results of the numerical analyses, the impact of 
Al and 
Bi scattering cross sections obtained using SCALE6.2/TSAR is disclosed on the Bi sample reactivity worth using Al reference and Bi test samples, although the uncertainty itself is small in the Bi sample reactivity worth.
Am fission rates in low-enriched uranium region at A-core of KUCAOizumi, Akito; Fukushima, Masahiro; Tsujimoto, Kazufumi; Yamanaka, Masao*; Pyeon, C. H.*
KURNS Progress Report 2019, P. 14, 2020/08
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 Americium-243 (Am) to Uranium-235 (
U) by using a single fission chambers in the KUCA. The result showed that the measured FRR of Am/U were 0.042 
0.002. These measured values will be used for verification of evaluated nuclear data by conducting detailed analyses.
Fukushima, Masahiro; Oizumi, Akito; Yamanaka, Masao*; Pyeon, C. H.*
KURNS Progress Report 2019, P. 143, 2020/08
For the design study of ADS, integral experimental data of nuclear characteristics of LBE is necessary to validate cross sections of lead (Pb) and bismuth (Bi). The calculation agree with experiment for the Bi sample worth. On the other hand, the calculation overestimates for the Pb sample worth.
Np and 
Am by accelerator-driven system at Kyoto University Critical AssemblyPyeon, C. H.*; Yamanaka, Masao*; Oizumi, Akito; Fukushima, Masahiro; Chiba, Go*; Watanabe, Kenichi*; Endo, Tomohiro*; Van Rooijen, W. G.*; Hashimoto, Kengo*; Sakon, Atsushi*; et al.
Journal of Nuclear Science and Technology, 56(8), p.684 - 689, 2019/08
Times Cited Count：12 Percentile：79.53(Nuclear Science & Technology)This study demonstrates, for the first time, the principle of nuclear transmutation of minor actinide (MA) by the accelerator-driven system (ADS) through the injection of high-energy neutrons into the subcritical core at the Kyoto University Critical Assembly. The main objective of the experiments is to confirm fission reactions of neptunium-237 (Np) and americium-241 (Am), and capture reactions of Np. Subcritical irradiation of Np and Am foils is conducted in a hard spectrum core with the use of the back-to-back fission chamber that obtains simultaneously two signals from specially installed test (Np or Am) and reference (uranium-235) foils. The first nuclear transmutation of Np and Am by ADS soundly implemented by combining the subcritical core and the 100 MeV proton accelerator, and the use of a lead-bismuth target, is conclusively demonstrated through the experimental results of fission and capture reaction events.
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.
Fukushima, Masahiro; Oizumi, Akito; Yamanaka, Masao*; Pyeon, C. H.*
KURNS Progress Report 2018, P. 143, 2019/08
For the design study of ADS, integral experimental data of nuclear characteristics of LBE is necessary to validate cross sections of lead (Pb) and bismuth (Bi). In present study, sample worth measurements were carried out with systematically changed mixing ratios of lead and bismuth, which would be complementary to the previous data of Pb and Bi samples individually measured in FY 2013 and FY 2017, respectively.
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.
Matsunami, Noriaki*; Fukushima, Junichi*; Sataka, Masao; Okayasu, Satoru; Sugai, Hiroyuki; Kakiuchida, Hiroshi*
Nuclear Instruments and Methods in Physics Research B, 268(19), p.3071 - 3075, 2010/10
Times Cited Count：13 Percentile：65.03(Instruments & Instrumentation)no abstracts in English
Katagiri, Masaki; Kishimoto, Maki; Ito, Hirokuni; ; Fukushima, Masao; Okawa, Hiroshi;
Nuclear Instruments and Methods in Physics Research A, 327, p.463 - 468, 1993/00
Times Cited Count：3 Percentile：43.05(Instruments & Instrumentation)no abstracts in English
Katagiri, Masaki; Kishimoto, Maki; Ito, Hirokuni; Fukushima, Masao; Okawa, Hiroshi; ; ; Tobita, Tsutomu
Journal of Nuclear Science and Technology, 29(10), p.957 - 965, 1992/10
no abstracts in English
; Uramoto, Toshimasa; Fukushima, Masao; ; ; ;
Proc. of the 3rd Asian Symp. on Research Reactor, p.285 - 292, 1991/00
no abstracts in English
*; Yasu, Takami; Shoji, Kenji; Fukushima, Isao; *; Shibuya, Jun; ; ; Yamamoto, Masao
PNC TN8440 87-190, 35 Pages, 1987/08
no abstracts in English
Takada, Fumiki; Kato, Yoshiaki; Omi, Masao; Wakai, Eiichi; Yamauchi, Kazuo*; Fukushima, Fumio*; Tokizawa, Koichi*
no journal, ,
no abstracts in English
Matsunami, Noriaki*; Fukushima, Jun*; Sataka, Masao; Okayasu, Satoru; Sugai, Hiroyuki; Kakiuchida, Hiroshi*
no journal, ,
no abstracts in English
Oizumi, Akito; Yamanaka, Masao*; Fukushima, Masahiro; Pyeon, C. H.*
no journal, ,
Sample reactivity worths of Lead (Pb) and Bismuth (Bi), which are a coolant candidate for the accelerator driven system (ADS), have been independently measured for the integral evaluations of their cross sections in the relatively hard neutron spectrum in the Kyoto University Critical Assembly (KUCA), respectively. There is a difference between C/E values of Pb and Bi which are obtained by comparing experimental analysis values using the Monte Carlo calculation code MCNP with the JENDL-4.0 nuclear data library with the measured values. In this experiment, in order to complement the measured values of simple substances of Pb and/or Bi, the sample reactivity worth measurements with systematically changed mixing ratio of them were carried out under the same conditions as the past experiments in the KUCA. First, the reproducibility of past experiments was confirmed from the measurement result of Pb simple substance (Pb100%). In addition, it was confirmed that the new measured values different in the lead volumetric filling ratio obtained in this experiment supplement between the measured values of simple substances of Pb (Pb100%) and Bi (Pb0%) in the past. In the future, the analyses of these series of experiments and the evaluations of C/E values will be carried out by using nuclear data libraries of JENDL, ENDF, and JEFF. By using the sensitivity analysis, we will identify the nuclides and their reactions responsible for the differences between the experimental and measured values and among the each nuclear data library.
