Bayesian uncertainty evaluation of Charpy ductile-to-brittle transition temperature for reactor pressure vessel steels

Takamizawa, Hisashi; Nishiyama, Yutaka; Hirano, Takashi*

Proceedings of ASME 2020 Pressure Vessels and Piping Conference (PVP 2020) (Internet), 7 Pages, 2020/08

https://doi.org/10.1115/PVP2020-21698

no abstracts in English

Spontaneous activation behavior of NiSn, an intermetallic catalyst, for hydrogen production via methanol decomposition

Fan, M.*; Xu, Y.*; Sakurai, Junya*; Demura, Masahiko*; Hirano, Toshiyuki*; Teraoka, Yuden; Yoshigoe, Akitaka

International Journal of Hydrogen Energy, 40(37), p.12663 - 12673, 2015/10

https://doi.org/10.1016/j.ijhydene.2015.05.197

The catalytic properties of single-phase NiSn powder in the production of hydrogen via the decomposition of methanol were investigated in isothermal tests at 713, 793, and 873 K. The catalytic activity of NiSn significantly increased with time at 793 and 873 K, but not at 713 K, suggesting that NiSn is spontaneously activated at temperatures above 793 K. At these temperatures, NiSn showed high selectivity for H and CO production and low selectivity for CH, CO, and HO production, indicating that methanol decomposition was the main reaction, and that side reactions such as methanation and water-gas shift reaction were suppressed. Surface analysis revealed that fine NiSn particles were formed during the reaction, accompanied by a small amount of deposited carbon. The formation of these particles was suggested to be the cause for the spontaneous activation of NiSn.

Present status of J-PARC linac

Oguri, Hidetomo; Hasegawa, Kazuo; Ito, Takashi; Chishiro, Etsuji; Hirano, Koichiro; Morishita, Takatoshi; Shinozaki, Shinichi; Ao, Hiroyuki; Okoshi, Kiyonori; Kondo, Yasuhiro; et al.

Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.389 - 393, 2014/10

http://www.pasj.jp/web_publish/pasj2014/proceedings/PDF/FSP0/FSP021.pdf

no abstracts in English

Catalytic performance of NiSn and NiSn for hydrogen production from methanol decomposition

Fan, M.*; Xu, Y.*; Sakurai, Junya*; Demura, Masahiko*; Hirano, Toshiyuki*; Teraoka, Yuden; Yoshigoe, Akitaka

Catalysis Letters, 144(5), p.843 - 849, 2014/05

https://doi.org/10.1007/s10562-014-1212-x

A Round robin program of master curve evaluation using miniature C(T) specimens; First round robin test on uniform specimens of reactor pressure vessel materials

Yamamoto, Masato*; Kimura, Akihiko*; Onizawa, Kunio; Yoshimoto, Kentaro*; Ogawa, Takuya*; Chiba, Atsushi*; Hirano, Takashi*; Sugihara, Takuji*; Sugiyama, Masanari*; Miura, Naoki*; et al.

Proceedings of 2012 ASME Pressure Vessels and Piping Conference (PVP 2012) (DVD-ROM), 7 Pages, 2012/07

Master curve (MC) approach for the fracture toughness evaluation is expected to be a powerful tool to assess the structural integrity of reactor pressure vessels (RPVs). In order to get sufficient number of reliable data for the MC approach from broken halves of surveillance test specimens for RPVs, the use of miniature specimens is necessary. For this purpose, a round robin test program on the miniature compact tension specimens (Mini-CT) of 4 mm thick for the MC approach of a Japanese RPV steel has been launched with the participation of academia, industries and a research institute in Japan. The program aims to verify the reliability of experimental data from Mini-CT, and to pick out further investigation items to be solved. As the first step of this program, four institutes carried out MC testing and evaluation using common test procedure and specimens. Valid reference temperature T was successfully obtained in each institute. However, the T values showed large differences with maximum of 34C. It was indicated on the reason of difference that there is a strong correlation between the T values and loading rate, which was selected by each institute per test standard.

Neoclassical tearing mode control using electron cyclotron current drive and magnetic island evolution in JT-60U

Isayama, Akihiko; Matsunaga, Go; Kobayashi, Takayuki; Moriyama, Shinichi; Oyama, Naoyuki; Sakamoto, Yoshiteru; Suzuki, Takahiro; Urano, Hajime; Hayashi, Nobuhiko; Kamada, Yutaka; et al.

Nuclear Fusion, 49(5), p.055006_1 - 055006_9, 2009/05

https://doi.org/10.1088/0029-5515/49/5/055006

no abstracts in English

Development of high power klystron, 2; Development of pulse-mode operation

Hirano, Koichiro; Emoto, Takashi; Wang, Y.; Sato, Isamu

PNC TN9410 98-068, 38 Pages, 1998/06

PNC-TN9410-98-068.pdf:0.92MB

A high power klystron has been developed as the RF source of the high power CW electron linac (10MeV, 100mA, 1.249135GHz). CW power of 1.2MW and efficiencies over 65% at a beam voltage 85kV were the design goal. Klystrons have been manufactured untill 1997. The klystron has achieved CW RF output power of 1040kW and beam voltage of 83kV at present. The power required for future applications is about four times the maximum power with CW-mode operation to accelerate electron beam at energy of 30MeV. We have redesigned the klystron, which is able to drive peak power 4.2MW with pulse-mode operation (100sec pulse width, 50 pps) without decreasing efficiency with CW operation. As peak power of 4.2MW at a beam voltage 147kV is required for pulse-mode operation, we have developed the electric gun, the RF window which endures peak power 4.2MW and the way of reducing apparently the output cavity Q optimized for CW-mode operation. The output cavity Q was decreased by two obstacles located on the long window. The klystron has achieved the maximum peak power, witch was 3.55MW with efficiency of 42% at a beam voltage 147kV in present. The unstable phenomenon of the power due to backward electrons hasn't been observed in the design condition. We have succeeded in the development of the klystron so as to be able to drive both CW mode and short pulse mode. The output cavity Q made effective use of two obstacles will be optimized by simulation codes to improve efficiency.

Injector commissioning of the PNC high power CW electron Linac

; ; Toyama, Shinichi; Nomura, Masahiro; ; Hirano, Koichiro

Journal of Pressure Vessel Technology, -(-), - Pages, 1998/00

None

Progress, status, and injector commissioning of the high power cw electron linac at PNC

Emoto, Takashi; Wang, Y.; Toyama, Shinichi; Nomura, Masahiro; Takei, Hayanori; Hirano, Koichiro; Yamazaki, Yoshio; Omura, Akiko; Tanimoto, Yasunori*; Tani, Satoshi

PNC TN9410 98-010, 51 Pages, 1997/12

PNC-TN9410-98-010.pdf:1.42MB

Design and construction of a high power CW (Continuous Wave) electron linac for studying feasibility of nuclear waste transmutation was started in l989 at PNC. The transmutation by photonuclear reaction using a electron accelerator has advantages of the small production for secondary radioactive waste and broad base of accelerator technology. The PNC accelerator (10 MeV, 20 mA average current, 20% duty) has been pre-commissioned. We have been very successful to produce 3 ms pulse width electron beam with 100 mA peak and energy about 2.9 MeV at present. The rest of the accelerating section was installed by March 1997. Studies are continued towards the designed goal of 100 mA beam with 4 msec pulse width and 50 Hz pulse repetition.

Development of high power klystron, 1

Hirano, Koichiro; Emoto, Takashi; Wang, Y.; Enomoto, Y; Sato, Isamu

PNC TN9410 96-071, 32 Pages, 1996/03

PNC-TN9410-96-071.pdf:1.11MB

(Objectives) A high power klystron that generates 1.2 MW radio frequency at 1.249135GHz is required for the high power CW electron linac development. The first prototype klystron was limited RF output of 330kW with CW-mode operation and 780kW with pulse-mode operation (50 msec pulse width, 1 pps) because the window temperature reached near the critical point of destruction by thermal stress. A long pill-box type beryllia window (long pill-box window) was designed and measured using a resonant ring in high power experiment. The long pill-box window withstood the RF output of 1.7MW(CW), that has been verified by the high power experiment. (Method) The standard pill-box prototype klystron was replaced with the long pill-box window. The high power test was carried out with the converted klystron. We measured maximum CW RF output power and observed the surface temperature rise of the ceramic window in the long pill-box. (Results)The temperature increase was 36 degrees with the long pill-box window when the klystron has achieved CW RF output power of 885kW, efficiency of 46%, and beam voltage of 85kV in present. The klystron has been optimized by simulation codes to improve better efficiency. The calculation shows the maximum efficiency is 70% using optimum parameters. (Conclusions)It was shown that the long pill-box window converted klystron had maximum transmission power that was fully satisfied with specifications of the high power klystron. The klystron with these results will be manufactured and the high power test will be carried out in 1997.