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Tokunaga, Sho; Horiguchi, Hironori; Nakamura, Takemi
JAEA-Technology 2023-001, 37 Pages, 2023/05
JAEA-Technology-2023-001.pdf:1.39MB
The cold neutron source (CNS) of the research reactor JRR-3 converts thermal neutrons generated in the reactor into low-energy cold neutrons by moderating them with liquid hydrogen stored in the moderator cell. Cold neutrons generated by the CNS are transported to experimental instruments using neutron conduits, and are used for many studies of physical properties, mainly in life science, polymer science, environmental science, etc. Improvement of cold neutron intensity is essential to maintain competitiveness with the world's research reactors in neutron science, and we are developing a new CNS that incorporates new knowledge. The current moderator cell for the CNS of JRR-3 is a stainless-steel container which is a canteen bottle type, and the cold neutron intensity can be improved by changing the material and shape. Therefore, the basic specifications of the new moderator cell were changed to aluminum alloy which has a smaller neutron absorption cross section, and the shape was optimized using a Monte Carlo code MCNP. Since these changes in specifications will result in changes in heat generation and heat transfer conditions, the CNS of JRR-3 was re-evaluated in terms of self-regulating characteristic, heat transport limits, heat resistance and pressure resistance, etc., to confirm its feasibility in thermal-hydraulic design. This report summarizes the results of the thermal-hydraulic design evaluation of the new moderator cell.
Teshigawara, Makoto; Ikeda, Yujiro*; Yan, M.*; Muramatsu, Kazuo*; Sutani, Koichi*; Fukuzumi, Masafumi*; Noda, Yohei*; Koizumi, Satoshi*; Saruta, Koichi; Otake, Yoshie*
Nanomaterials (Internet), 13(1), p.76_1 - 76_9, 2023/01
Times Cited Count：2 Percentile：71.03(Chemistry, Multidisciplinary)To enhance neutron intensity below cold neutrons, it is proposed that nanosized graphene aggregation could facilitate neutron coherent scattering under particle size conditions similar to nanodiamond. It might also be possible to use it in high neutron radiation conditions due to graphene's strong sp2 bonds. Using the RIKEN accelerator-driven compact neutron source and iMATERIA at J-PARC, we performed neutron measurement experiments, total neutron cross-section, and small-angle neutron scattering on nanosized graphene aggregation. The measured data revealed, for the first time, that nanosized graphene aggregation increased the total cross-sections and small-angle scattering in the cold neutron energy region, most likely due to coherent scattering, resulting in higher neutron intensities, similar to nanodiamond.
Ma, B.*; Teshigawara, Makoto; Wakabayashi, Yasuo*; Yan, M.*; Hashiguchi, Takao*; Yamagata, Yutaka*; Wang, S.*; Ikeda, Yujiro*; Otake, Yoshie*
Nuclear Instruments and Methods in Physics Research A, 995, p.165079_1 - 165079_7, 2021/04
Times Cited Count：2 Percentile：33.7(Instruments & Instrumentation)We have optimized a cold neutron moderator to be operated at the RIKEN accelerator-driven compact neutron source. We selected a safe and easy to manage material, mesitylene, as the RANS cold moderator. An efficient moderator system was designed by studying and optimizing a coupled cold neutron moderator of mesitylene at 20 K with a polyethylene (PE) pre-moderator at room temperature in the slab geometry with Particle and Heavy Ion Transport code System (PHITS) simulations. The parameters of mesitylene and PE thickness, the reflector, and the shielding configuration were studied to increase cold neutron intensities. Consequently, an integrated cold neutron intensity of 1.15
10
n/cm
/
A at 2 m from the neutron-producing target was finally achieved, which was 12 times higher than that of the current PE moderator. The results showed attractive application prospect of mesitylene as cold neutron moderator material.
Arai, Masaji; Tamura, Itaru; Hazawa, Tomoya
JAEA-Technology 2015-010, 52 Pages, 2015/05
JAEA-Technology-2015-010.pdf:7.11MB
In the Department of Research Reactor and Tandem Accelerator, developments of high-performance CNS moderator vessel that can produce cold neutron intensity about two times higher compared to the existing vessel have been performed in the second medium term plans. We compiled this report about the technological development to solve several problems with the design and manufacture of new vessel. In the present study, design strength evaluation, mockup test, simulation for thermo-fluid dynamics of the liquid hydrogen and strength evaluation of the different-material-bonding were studied. By these evaluation results, we verified that the developed new vessel can be applied to CNS moderator vessel of JRR-3.
Oyama, Yukio; Ikeda, Yujiro
Hoshasen To Sangyo, (107), p.45 - 51, 2005/09
JAERI and KEK are jointly conducting high intensity proton accelerator project (J-PARC). The outline of the J-PARC project and a design concept of the neutron source facility at J-PARC are described in detail.
Aso, Tomokazu; Sato, Hiroshi; Kaminaga, Masanori; Hino, Ryutaro; Monde, Masanori*
Proceedings of ICANS-XVI, Volume 2, p.935 - 944, 2003/07
no abstracts in English
Aso, Tomokazu; Kaminaga, Masanori; Hino, Ryutaro; Monde, Masanori*
Proceedings of 11th International Conference on Nuclear Engineering (ICONE-11) (CD-ROM), 8 Pages, 2003/04
no abstracts in English
Sakurai, Fumio; Horiguchi, Yoji; Kobayashi, Shinsho; Takayanagi, Masaji
Physica B; Condensed Matter, 311(1-2), p.7 - 13, 2002/01
Times Cited Count：9 Percentile：45.19(Physics, Condensed Matter)no abstracts in English
; ; ; Kaieda, Keisuke
KAERI/GP-128/98, p.205 - 221, 1998/00
no abstracts in English
Watanabe, Noboru*; Teshigawara, Makoto*; Takada, Hiroshi; Nakashima, Hiroshi; Oyama, Yukio; *; Kai, Tetsuya; Ikeda, Yujiro; Kosako, Kazuaki*
Proc. of 14th Meeting of the Int. Collaboration on Advanced Neutron Sources (ICANS-14), 2, p.728 - 742, 1998/00
no abstracts in English
Kumai, Toshio; ; Takayanagi, Masaji
ASRR-V: Proc., 5th Asian Symp. on Research Reactors, 2, p.619 - 626, 1996/00
no abstracts in English
Suzuki, Masatoshi; *; Ichikawa, Hiroki
JAERI-M 92-201, 17 Pages, 1993/01
no abstracts in English
Kumai, Toshio; *; ; Akutsu, Cho; Takahashi, Hidetake
JAERI-M 89-114, 32 Pages, 1989/09
no abstracts in English
; *; ;
JAERI-M 87-006, 19 Pages, 1987/02
no abstracts in English
Aso, Tomokazu; Teshigawara, Makoto; Hasegawa, Shoichi; Muto, Hideki*; Aoyagi, Katsuhiro*; Takada, Hiroshi
no journal, ,
Tokunaga, Sho; Nakamura, Takemi; Kikuchi, Masanobu; Noguchi, Hironori*; Oda, Yasushi*
no journal, ,
In order to examine a hydrogen flow analysis method for the high-performance moderator vessel including the entire CNS system, a pipe network analysis of the entire system including the moderator vessel using RELAP5/MOD3.2 and a CFD analysis of the moderator vessel using ANSYS-FLUENT which added physical models that were not considered in a conceptual design were evaluated in combination. The validity of these calculations was compared using Sudo's equation, which is in good agreement with the results of the out-of-reactor operating test in the current canteen bottle moderator vessel.
Kikuchi, Masanobu; Nakamura, Takemi; Tokunaga, Sho; Oda, Yasushi*
no journal, ,
The vessel shape was changed from the conceptual design to take manufacturability into consideration. The inner surface of the vessel is filleted, and the flat section is reinforced and tapered. To verify its validity, check for plastic deformation at maximum pressure.
