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Takeda, Takeshi
JAEA-Data/Code 2023-012, 75 Pages, 2023/10
JAEA-Data-Code-2023-012.pdf:4.45MB
An experiment denoted as TR-LF-15 was conducted on June 11, 2014 using the Large Scale Test Facility (LSTF) in the Rig of Safety Assessment-V (ROSA-V) Program. The ROSA/LSTF experiment TR-LF-15 simulated accident management (AM) actions during a station blackout transient with TMLB' scenario with pump seal loss-of-coolant accident (LOCA) in a pressurized water reactor (PWR). This scenario is featured by loss of auxiliary feedwater functions. The pump seal LOCA was simulated by a 0.1% cold leg break. The test assumptions included total failure of both high pressure injection system and low pressure injection system of emergency core cooling system (ECCS). Also, it was presumed non-condensable gas (nitrogen gas) inflow to the primary system from accumulator (ACC) tanks of ECCS. When steam generator (SG) secondary-side collapsed liquid level dropped to a certain low liquid level, the primary pressure turned to rise. After the SG secondary-side became voided, the safety valve of a pressurizer cyclically opened which led to loss of primary coolant. Core uncovery thus took place owing to core boil-off at high pressure. When an increase of 10 K was confirmed in cladding surface temperature of simulated fuel rods, SG secondary-side depressurization was started as the first AM action. At that time, the safety valves in both SGs were fully opened. Primary depressurization was initiated by completely opening the pressurizer safety valve as the second AM action with some delay after the first AM action onset. When the SG secondary-side pressure lowered to 1.0 MPa following the first AM action, water was injected into the secondary-side of both SGs via feedwater lines with low-head pumps as the third AM action. A reduction in the primary pressure was accelerated because the heat removal from the SG secondary-side system resumed shortly after the third AM action initiation.
Onoda, Yuichi; Uchita, Masato*; Tokizaki, Minako*; Okazaki, Hitoshi*
Proceedings of 29th International Conference on Nuclear Engineering (ICONE 29) (Internet), 6 Pages, 2022/08
The safety analyses were carried out to confirm the sufficiency of the function of the plant protection system against the pump/diagrid link rupture. The target plant is a pool-type SFR of about 600 MWe class equipped with an axially homogeneous core currently under development in Japan. In the pool-type SFR, the primary system piping connects primary pump and the high-pressure sodium plenum located at the inlet of fuel sub-assemblies and called "pump/diagrid link". Because this piping is submerged in the reactor vessel, it is difficult to detect small scale sodium leakage in this piping, and thus a certain large pipe break like guillotine should be assumed and evaluated as a design basis event. In order to confirm the detectability of pump/diagrid link rupture by safety protection system signals, a series of analyses of the guillotine break for a pump/diagrid link were carried out. Sensitivity study had also been performed to consider the uncertainty of the reactivity coefficient in the analyses. The sufficiency of the function of the plant protection system against the pump/diagrid link rupture was confirmed by the analysis results that at least two signals are transmitted for the detection of the event, which is the development target of the plant protection system in pool-type SFR.
Sakai, Kenji; Oku, Takayuki; Okudaira, Takuya; Kai, Tetsuya; Harada, Masahide; Hiroi, Kosuke; Hayashida, Hirotoshi*; Kakurai, Kazuhisa*; Shimizu, Hirohiko*; Hirota, Katsuya*; et al.
JPS Conference Proceedings (Internet), 33, p.011116_1 - 011116_6, 2021/03
In neutron fundamental physics, study of correlation term 
of a neutron spin 
and a target nuclear spin 
is important because term interferes to parity non-conserving (PNC) and time reversal non-conserving terms. For this study, a xenon (Xe) is an interesting nucleus because it has been observed an enhancement of PNC effect around neutron resonance peaks, and polarizes up to 
by using a spin exchange optical pumping (SEOP) method. We would plan to develop a polarized Xe gas target with a compact in-situ SEOP system, and to study term by utilizing epithermal neutron beams supplied from a high intense pulsed spallation neutron source. As the first step, we attempted to measure neutron polarizing ability caused by term at a 9.6 eV s-wave resonance peak of 
Xe at BL10 in MLF, by detecting change 
of ratio between neutron transmissions with the polarized and unpolarized Xe target. After demonstrating that our apparatus could detect small change (
) of neutron transmissions caused by Doppler broadening effect, a signified value of has been obtained as preliminary results. For analyzing the obtained in detail, we are improving our nuclear magnetic resonance and electron paramagnetic resonance systems for evaluating Xe polarization independently of neutron beams.
Takeda, Takeshi; Otsu, Iwao
Journal of Energy and Power Sources, 2(7), p.274 - 290, 2015/07
plasma operationTamai, Hiroshi; Akiba, Masato; Azechi, Hiroshi*; Fujita, Takaaki; Hamamatsu, Kiyotaka; Hashizume, Hidetoshi*; Hayashi, Nobuhiko; Horiike, Hiroshi*; Hosogane, Nobuyuki; Ichimura, Makoto*; et al.
Nuclear Fusion, 45(12), p.1676 - 1683, 2005/12
Times Cited Count：15 Percentile：45.53(Physics, Fluids & Plasmas)Design studies are shown on the National Centralized Tokamak facility. The machine design is carried out to investigate the capability for the flexibility in aspect ratio and shape controllability for the demonstration of the high-beta steady state operation with nation-wide collaboration, in parallel with ITER towards DEMO. Two designs are proposed and assessed with respect to the physics requirements such as confinement, stability, current drive, divertor, and energetic particle confinement. The operation range in the aspect ratio and the plasma shape is widely enhanced in consistent with the sufficient divertor pumping. Evaluations of the plasma performance towards the determination of machine design are presented.
Kiriyama, Hiromitsu; Yamakawa, Koichi; Kageyama, Nobuto*; Miyajima, Hirofumi*; Kan, Hirofumi*; Yoshida, Hidetsugu*; Nakatsuka, Masahiro*
Japanese Journal of Applied Physics, Part 1, 44(10), p.7464 - 7471, 2005/10
Times Cited Count：2 Percentile：9.29(Physics, Applied)no abstracts in English
Maruyama, Yoichiro
Optical Engineering, 44(9), p.094202_1 - 094202_3, 2005/09
Times Cited Count：1 Percentile：7.76(Optics)A high average power BBO optical parametric oscillator pumped by a Nd:YAG laser second harmonic is demonstrated at the pulse repetition frequency of 0.5 kHz. Average power of 5.4 W (10.8 mJ) with the energy conversion efficiency of 45% is obtained for Type-I BBO OPO. The output power still increasing and undesirarble thermal effects are not observed.
Kiriyama, Koji*; Shiwaku, Hideaki
JAERI-Tech 2005-044, 16 Pages, 2005/08
JAERI-Tech-2005-044.pdf:1.31MB
Stabilizing methods for vacuum exhaustion units in the optics section of the beamline have been developed on BL11XU at SPring-8. In this study, we especially focus on the vibrations from scroll pumps in the vacuum exhaustion units. Vibration frequencies are measured directly on the scroll pump under multiple conditions. The results showed that countermeasures to restrain the 30Hz vibration from scroll pumps on the beamline which was caused by working scroll pump are (1) using a damper for scroll pump, (2) pulling out the scroll pump from a vacuum unit support, and (3) settling flexible tubes and the scroll pump on the floor. These methods successfully removed the mechanical vibrations of the scroll pumps. As a result, the amplitude of 30Hz vibration on the monochromator crystals was decreased from 3.3
10-5mm to 6.210-6mm. The developed method in the present study on BL11XU is expected to apply to the similar vacuum units at the other beamlines.
Maruyama, Yoichiro; Kubomura, Hiroyuki*; Kasamatsu, Tadashi*; Matsuoka, Shinichi*; Nakano, Fumihiko*; Kan, Hirofumi*
JAERI-Tech 2004-056, 14 Pages, 2004/09
JAERI-Tech-2004-056.pdf:3.49MB
A high average power tunable solid state laser is pumped by the second harmonic of LD-pumped high repetition rate Nd:YAG laser consisting of a single-longitudinal-mode oscillator and amplifiers. To operate the Nd:YAG laser oscillator with a single-longitudinal-mode by injection seeding, the cavity length control is required to coincide the resonant frequency of Nd:YAG laser oscillator with the frequency of seeder. For this purpose, a cavity length control system of the Nd:YAG laser oscillator is developed and the characteristics are studied. With this system, the cavity length is controlled at the pulse repetition rate of 0.5 kHz and the single frequency operation for more than three hours is realized.
Kikuchi, Kenji; Saito, Shigeru; Kurata, Yuji; Futakawa, Masatoshi; Sasa, Toshinobu; Oigawa, Hiroyuki; Wakai, Eiichi; Umeno, Makoto*; Mizubayashi, Hiroshi*; Miura, Kuniaki*
JSME International Journal, Series B, 47(2), p.332 - 339, 2004/05
Lead bismuth eutectic (LBE) is favored by spallation neutron sources and coolant in the sub-critical reactor at the accelerator driven nuclear transmutation system (ADS). Technical issues of ADS are material technology of how to compromise with flowing lead bismuth, high-energy proton accelerator technology and a sub-critical reactor system technology. This paper describes LBE technology developed at JAERI. First a scenario in order to realize the ADS is shown. The concept of spallation target test facility is introduced with a target design of thermo-fluid dynamics. Base data of flow rate and temperature of Pb-Bi during LBE circulation are described. The results of LBE loop operation under the flowing conditions of target design concept are reported. The stagnant corrosion tests were done to know the controlling parameters among the various steels. The tube-type oxygen sensor with having the solid electrolyte was studied. Cleaning techniques were developed to remove LBE from materials.
Kurata, Yuji; Kikuchi, Kenji; Saito, Shigeru; Kamata, Kinya*; Kitano, Teruaki*; Oigawa, Hiroyuki
Proceedings of 4th International Workshop on the Utilisation and Reliability of High Power Proton Accelerators, p.267 - 277, 2004/05
R&D on lead-bismuth technology have been conducted for accelerator driven system. From the test results of 316SS using JLBL-1 for 3000h without active oxygen control, mass transfer from high temperature to low temperature parts was observed. It was found that deposition of Pb/Bi and Fe-Cr grains in the annular channel of the electro-magnetic pump caused plugging and decrease in flow rate. The modification of the loop system brought about a good effect on operation. Significant erosion/corrosion was not observed in the experiment using MES loop for 1000h under 10
wt.% oxygen condition. The results of static corrosion tests showed the following: corrosion depth decreased at 450
C with increasing Cr content in steels while corrosion depth of JPCA and 316SS became larger due to ferritization caused by dissolution of Ni and Cr at 550C. Si-added steel exhibited good corrosion resistance at 550C.
Kinoshita, Hidetaka; Haga, Katsuhiro; Kaminaga, Masanori; Hino, Ryutaro
Journal of Nuclear Science and Technology, 41(3), p.376 - 384, 2004/03
Times Cited Count：3 Percentile：23.52(Nuclear Science & Technology)A construction of the spallation neutron source is being promoted under the Japan Proton Accelerator Research Complex (J-PARC) Project. A mercury circulation system has been designed to supply mercury to the target stably. It was necessary to make clear a mercury pump performance, erosion rate under the mercury flowing condition and an amount of remaining mercury after draining from the viewpoints of evaluating lifetime of piping and establishing remote handling scenario of mercury components. The mercury pump performance, the erosion rates and the amount of remained mercury were investigated by using a mercury experimental loop with an experimental gear pump. The discharged flow rates of the experimental gear pump are sufficient and it is increased linearly with the rotation speed. Erosion rates were found to be so small that decrease of piping wall thickness would be estimated 660 
m after 30-year operation under the rated velocity of 0.7 m/s. For the amount of remaining mercury, remaining rates of weight was estimated at 50.7 g/m
.
Daido, Hiroyuki
Reports on Progress in Physics, 65(10), p.1513 - 1576, 2002/10
Times Cited Count：190 Percentile：75.22(Physics, Multidisciplinary)no abstracts in English
Hiroki, Seiji; Abe, Tetsuya; Tanzawa, Sadamitsu; Nakamura, Junichi*; Obayashi, Tetsuro*
JAERI-Tech 2002-056, 11 Pages, 2002/07
JAERI-Tech-2002-056.pdf:0.79MB
no abstracts in English
Guillemet, L.*; Jager, B.*; Haange, R.*; Hamada, Kazuya; Hara, Eiji*; Kalinin, G.*; Kato, Takashi; Millet, F.*; Shatil, N.*
Proceedings of 19th International Cryogenic Engineering Conference (ICEC-19), p.105 - 108, 2002/07
Japan Atomic Energy Research Institute has designed a ITER cryoplant and cryo-distribution in the international collaboration. The ITER cryoplant that will be the largest cryogenic system for the Fusion facility in the world, is designed to be stable in operation despite the pulsed nature of heat deposition in the magnet system. The refrigeration capacity of cryoplant is 48 kW at 4.5 K of refrigeration power and 0.16 kg/s of supercritical helium supply. In the cryoplant, a supercritical helium pump and a cold compressor is applied, based on the successful achievement of cryogenic system for the ITER central solenoid model coil.
Kritmaitree, P.; Akiyama, Mitsunobu*; Hino, Ryutaro; Kaminaga, Masanori; Terada, Atsuhiko*
Journal of Nuclear Science and Technology, 39(1), p.101 - 107, 2002/01
Times Cited Count：6 Percentile：39.54(Nuclear Science & Technology)The paper presents analytical results of suction process of a volumetric scroll pump, which will be developed for circulating liquid hydrogen in a cold moderator system. The multi-block grid generation approch has been applied to generate a moving boundaries computational model. The finer mesh patterns have been generated in the near-wall regions. The analysis has been carried out under liquid hydrogen flow conditions. The analytical results show that at the end of suction process the relative pressures increase significantly in a pocket while decrease continuously in another pocket. This phenomenon might damage scroll pump components if the high-pressure side is too high and/or the low-pressure side is too low until the cavitations occur. Therefore, the pockect should open to the discharge chamber before it closes and separates from the suction chamber in order to prevent the cavitations and extremely high-pressure regions.
Sugimoto, Makoto
JAERI-Research 2000-069, 134 Pages, 2001/03
JAERI-Research-2000-069.pdf:7.46MB
no abstracts in English
Higashijima, Satoru; Kubo, Hirotaka; Sugie, Tatsuo; Nakano, Tomohide; Konoshima, Shigeru; Tamai, Hiroshi; Shimizu, Katsuhiro; Sakasai, Akira; Asakura, Nobuyuki; Sakurai, Shinji; et al.
Journal of Nuclear Materials, 290-293, p.623 - 627, 2001/03
Times Cited Count：6 Percentile：44.09(Materials Science, Multidisciplinary)no abstracts in English
Kato, Takashi
Tabo Kikai, 28(9), p.536 - 545, 2000/09
no abstracts in English
Utsumi, Takayuki*; Sasaki, Akira
Dai-14-Kai Suchi Ryutai Rikigaku Shimpojiumu Koen Yoshishu, 4 Pages, 2000/00
no abstracts in English
