Study on eutectic melting behavior of control rod materials in core disruptive accidents of sodium-cooled fast reactors, 1; Project overview and progress until 2018

Yamano, Hidemasa; Takai, Toshihide; Furukawa, Tomohiro; Kikuchi, Shin; Emura, Yuki; Kamiyama, Kenji; Fukuyama, Hiroyuki*; Higashi, Hideo*; Nishi, Tsuyoshi*; Ota, Hiromichi*; et al.

Proceedings of 2020 International Conference on Nuclear Engineering (ICONE 2020) (Internet), 10 Pages, 2020/08

https://doi.org/10.1115/ICONE2020-16102

One of the key issues in a core disruptive accident (CDA) evaluation in sodium-cooled fast reactors is eutectic reactions between boron carbide (BC) and stainless steel (SS) as well as its relocation. Such behaviors have never been simulated in CDA numerical analyses in the past, therefore it is necessary to develop a physical model and incorporate the model into the CDA analysis code. This study focuses on BC-SS eutectic melting experiments, thermophysical property measurement of the eutectic melt, and physical model development for the eutectic melting reaction. The eutectic experiments involve the visualization experiments, eutectic reaction rate experiments and material analyses. The thermophysical properties are measured in a range from solid to liquid state. The physical model is developed for a severe accident computer code based on the measured data of the eutectic reaction rate and the physical properties. This paper describes the project overview and progress of experimental and analytical studies conducted until 2018. Specific results in this paper are boron concentration distributions of solidified BC-SS eutectic sample in the eutectic melting experiments, which would be used for the validation of the eutectic physical model implemented into the computer code.

Final design of the energy-resolved neutron imaging system "RADEN" at J-PARC

Shinohara, Takenao; Kai, Tetsuya; Oikawa, Kenichi; Segawa, Mariko; Harada, Masahide; Nakatani, Takeshi; Oi, Motoki; Aizawa, Kazuya; Sato, Hirotaka*; Kamiyama, Takashi*; et al.

Journal of Physics; Conference Series, 746, p.012007_1 - 012007_6, 2016/00

https://doi.org/10.1088/1742-6596/746/1/012007

no abstracts in English

Measurements of neutron capture cross sections of Sn and Sn with J-PARC/MLF/ANNRI

Kimura, Atsushi; Hirose, Kentaro; Nakamura, Shoji; Harada, Hideo; Hara, Kaoru; Hori, Junichi*; Igashira, Masayuki*; Kamiyama, Takashi*; Katabuchi, Tatsuya*; Kino, Koichi*; et al.

Nuclear Data Sheets, 119, p.150 - 153, 2014/05

https://doi.org/10.1016/j.nds.2014.08.042

Measurements of capture rays from the neutron resonances of Se and Se at the J-PARC/MLF/ANNRI

Hori, Junichi*; Yashima, Hiroshi*; Nakamura, Shoji; Furutaka, Kazuyoshi; Hara, Kaoru; Harada, Hideo; Hirose, Kentaro; Kimura, Atsushi; Kitatani, Fumito; Koizumi, Mitsuo; et al.

Nuclear Data Sheets, 119, p.128 - 131, 2014/05

https://doi.org/10.1016/j.nds.2014.08.036

In this work, we measured the capture rays from the neutron resonances of Se and Se. A neutron time-of-flight method was adopted for the measurements with a 4 Ge spectrometer installed at the Accurate Neutron-Nucleus Reaction measurement Instrument (ANNRI) in the J-PARC Material and Life science experimental Facility (MLF). The -ray pulse-height spectra corresponding to the 27-eV resonance of Se and the 113-, 212-, 291-, 342-, 690- and 864-eV resonances of Se were obtained by gating on the TOF regions, respectively. The relative intensities of those primary transitions were derived and compared with the previous experimental data. For the 27-eV resonance of Se, a strong primary transition to the 293-keV state was observed. As for Se, the quite differences of the decay pattern were found between the resonances.

Bipartite magnetic parent phases in the iron oxypnictide superconductor

Hiraishi, Masatoshi*; Iimura, Soshi*; Kojima, Kenji*; Yamaura, Junichi*; Hiraka, Haruhiro*; Ikeda, Kazutaka*; Miao, P.*; Ishikawa, Yoshihisa*; Torii, Shuki*; Miyazaki, Masanori*; et al.

Nature Physics, 10(4), p.300 - 303, 2014/04

https://doi.org/10.1038/nphys2906

Cross section measurement of Sn using ANNRI-NaI(Tl) spectrometer at J-PARC

Hirose, Kentaro; Furutaka, Kazuyoshi; Hara, Kaoru; Harada, Hideo; Kimura, Atsushi; Kitatani, Fumito; Koizumi, Mitsuo; Nakamura, Shoji; Oshima, Masumi; Toh, Yosuke; et al.

JAEA-Conf 2013-002, p.173 - 178, 2013/10

https://doi.org/10.11484/jaea-conf-2013-002

Neutron-capture cross-sections of Cm and Cm measured with an array of large germanium detectors in the ANNRI at J-PARC/MLF

Kimura, Atsushi; Fujii, Toshiyuki*; Fukutani, Satoshi*; Furutaka, Kazuyoshi; Goko, Shinji*; Hara, Kaoru; Harada, Hideo; Hirose, Kentaro; Hori, Junichi*; Igashira, Masayuki*; et al.

Journal of Nuclear Science and Technology, 49(7-8), p.708 - 724, 2012/07

https://doi.org/10.1080/00223131.2012.693887

A "4 Ge spectrometer" for measurements of neutron capture cross sections by the time-of-flight method at the J-PARC/MLF/ANNRI

Kin, Tadahiro; Furutaka, Kazuyoshi; Goko, Shinji*; Harada, Hideo; Kimura, Atsushi; Kitatani, Fumito; Nakamura, Shoji; Ota, Masayuki*; Oshima, Masumi; Toh, Yosuke; et al.

Journal of the Korean Physical Society, 59(2), p.1769 - 1772, 2011/08

https://doi.org/10.3938/jkps.59.1769

For the developments of advanced reactors such as fast breeder reactors or accelerator driven systems, nuclear data of minor actinides (MAs) and long-lived fission products (LLFPs) are important. However, these data are insufficient at present in quantity and quality. To overcome/improve such a situation, we have developed a 4 germanium spectrometer to measure neutron capture cross sections of MAs and LLFPs by the time-of-flight (TOF) method. The spectrometer was installed in the MLF in the J-PARC. At the conference, we will report a result of a measurement of the neutron capture cross section for gold by the TOF method to develop an analysis method. The analysis methods will be used for MAs and LLFPs. During the experiment for gold, the accelerator of J-PARC was operated in so called "double-bunch mode". In the mode, protons injected to the Japan Spallation Neutron Source (JSNS) have a time structure. The time structure affects TOF measurements. Mainly the accelerator is operated in the mode, it is important to know the effect. We found dead-time effect can be corrected by using a random-pulse generator. Background components can be removed with results of measurements of a blank sample. The cross section measured was normalized by the value in ENDF B/VII at the thermal energy. Finally, the cross section of gold in the incident neutron energy range from the thermal to 10 keV was obtained. Because the result is in good agreement with ENDF B/VII, we found the analysis method can be applied for experimental data obtained with the spectrometer.

Study of neutron capture reactions using the 4 Ge spectrometer

Harada, Hideo; Goko, Shinji*; Kimura, Atsushi; Ota, Masayuki*; Oshima, Masumi; Kitatani, Fumito; Toh, Yosuke; Furutaka, Kazuyoshi; Kin, Tadahiro; Koizumi, Mitsuo; et al.

Journal of the Korean Physical Society, 59(2), p.1547 - 1552, 2011/08

https://doi.org/10.3938/jkps.59.1547

For the improvement of the accuracy on the neutron capture cross sections, a 4 Ge spectrometer was developed. The 4 Ge spectrometer is a unique tool due to its superior energy resolution for studying properties on neutron capture reactions, not only capture cross sections but also resonance identification, -ray intensity distribution, and spin-parity assignment. For example, its performance on the resonance identification was demonstrated using a Ag sample. On the measurement of a -ray intensity distribution for each resonance, the results of U will be shown. Using the 4 Ge spectrometer, the measurements of neutron capture cross sections were started at the J-PARC/MLF/ANNRI. The preliminary results on the measurements of neutron capture cross sections will be discussed mainly based on measurements of neutron capture cross sections for Am, together with related techniques.

Measurement of neutron capture rays from the resonances of Zr and Zr at the J-PARC/MLF/ANNRI

Hori, Junichi*; Furutaka, Kazuyoshi; Goko, Shinji*; Harada, Hideo; Kimura, Atsushi; Kin, Tadahiro; Kitatani, Fumito; Koizumi, Mitsuo; Nakamura, Shoji; Ota, Masayuki*; et al.

Journal of the Korean Physical Society, 59(2), p.1777 - 1780, 2011/08

https://doi.org/10.3938/jkps.59.1777

The prompt rays from the neutron capture reactions by Zr and Zr were measured. A neutron time-of-flight (TOF) method was adopted with a 4 Ge spectrometer installed at the Accurate Neutron-Nucleus Reaction measurement Instrument (ANNRI) in the J-PARC Material and Life science experimental Facility (MLF). The -ray pulse-height spectra corresponding to the 292-eV resonance of Zr and the 301-eV resonance of Zr were obtained by gating on the TOF regions, respectively. The relative intensities of those transitions were derived. Moreover, we have demonstrated the nuclide discrimination technique by identifying Zr resonances (isotopic composition of 5.3%) in the measurement of Zr sample. This technique can be applicable to the neutron capture measurement for a small amount of sample expected in case of long lived fission products (LLFPs) such as Zr.