Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Onoda, Yuichi; Uchita, Masato*; Tokizaki, Minako*; Okazaki, Hitoshi*
Nuclear Technology, 20 Pages, 2025/00
Times Cited Count：0 Percentile：0.00(Nuclear Science & Technology)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.
Takano, Kazuya; Sakamoto, Yoshihiko; Morohoshi, Kyoichi*; Okazaki, Hitoshi*; Gima, Hiromichi*; Teramae, Takuma*; Ikarimoto, Iwao*; Botte, F.*; Dirat, J.-F.*; Dechelette, F.*
Proceedings of 2019 International Congress on Advances in Nuclear Power Plants (ICAPP 2019) (Internet), 8 Pages, 2019/05
ASTRID has the objective to integrate innovative options in order to prepare the 4th generation reactors. In ASTRID, large number of tubes are installed above each fuel subassembly to monitor the core. These instrumentations such as thermocouples (TC) and Failed Fuel Detection and Location (FFDL) systems are integrated into Above Core Structure (ACS) with various sizes tubes. In the present study, the routing study for TC tubes and FFDL tubes was performed with 3D modeling and mock-up experiment of the ACS designed for ASTRID with 1500 MW thermal power in order to clarify the integration process and secure the design hypotheses. Although some problems on fabricability were found in the mock-up experiment, the possible solutions were proposed. The present study gives manufacturing feedback to design team and will contribute to increase the knowledge for ACS design and fabricability.
Ishikawa, Nobuyuki; Chikazawa, Yoshitaka; Fujita, Kaoru; Yamada, Yumi*; Okazaki, Hitoshi*; Suzuki, Shinichi*
Proceedings of 2012 International Congress on Advances in Nuclear Power Plants (ICAPP '12) (CD-ROM), p.483 - 489, 2012/06
The development of safety protection system for JSFR is progressed in terms of logic circuits, selection of trip signals and its setting values for reactor trip. In addition, it is necessitated to evaluate the satisfaction for requirements of the safety protection system by safety analyses considering comprehensive parameter ranges. For this purpose, we will report the current status of the development focusing on the evaluation results for satisfaction of safety protection system based on safety standard.
Aizawa, Kosuke; Chikazawa, Yoshitaka; Ishikawa, Nobuyuki; Kubo, Shigenobu; Okazaki, Hitoshi*; Mito, Makoto*; Tozawa, Katsuhiro*; Hayashi, Masateru*
Proceedings of 2012 International Congress on Advances in Nuclear Power Plants (ICAPP '12) (CD-ROM), p.465 - 474, 2012/06
A conceptual design study of an advanced sodium-cooled fast reactor JSFR has progressed in the "Fast Reactor Cycle Technology Development (FaCT)" project in Japan. JSFR has two failed fuel detection systems in the core. One is a failed fuel detection (FFD) system which continuously monitors a fission product from failed fuel subassembly. The other is a failed fuel detection and location (FFDL) system which locates when it receives signals from FFD. In this study, requirements to the FFD-DN and the FFD-DN design to meet the requirements were investigated for the commercial and demonstration JSFR. For the FFDL systems, experiences in the previous fast reactors and the research and development of FFDL system for JSFR were investigated. Operation experiences of the Selector-valve FFDL system were accumulated in PFR and Phenix. Tagging-gas system experiences were accumulated in EBR-II and FFTF.
Fujine, Sachio; Murata, Mikio; Abe, Hitoshi; Takada, Junichi; Tsukamoto, Michio; Miyata, Teijiro*; Ida, Masaaki*; Watanabe, Makio; Uchiyama, Gunzo; Asakura, Toshihide; et al.
JAERI-Research 99-056, p.278 - 0, 1999/09
JAERI-Research-99-056.pdf:22.73MB
no abstracts in English
Takano, Hitoshi*; Sakuramoto, Yuji*; Okazaki, Kazuhiko*
JNC TJ1400 2005-013, 132 Pages, 1987/06
JNC-TJ1400-2005-013.pdf:8.43MB
The literature investigation and field survey done to get basic data to clarify the weathering characterristics of natureal glass from Japan as a study on geological disposal of highly radioactive waste.
Makino, Hitoshi; Hioki, Kazumasa; Umeki, Hiroyuki; Sugiyama, Naoki; Ochi, Yasuhiro; Okazaki, Wataru; Naito, Morimasa; Miyahara, Kaname; Okubo, Hiroo*; Ishihara, Yoshinao*
no journal, ,
This presentation will introduce developmenmt of methodology for optimisation of waste disposal considering variation of waste charcteristics from LWR cycle and also advanced cycle.
Onoda, Yuichi; Uchita, Masato*; Tokizaki, Minako*; Okazaki, Hitoshi*
no journal, ,
The safety analyses were carried out to confirm the sufficiency of the function of the plant protection system against the pump/diagrid link rupture, which is a candidate of the design basis event in pool type SFR. Sensitivity has been studied for the parameters which are thought significantly to affect the detection of the pump/diagrid link rupture, such as initial reactor power (at rated and 30% power operation), reactivity feedbacks and so forth. The sufficiency of the function was confirmed by the analysis results that at least two signals are transmitted for the detection of the pump/diagrid link rupture, which is the development target of the plant protection system in pool type SFR.
Nabeshima, Kunihiko; Aizawa, Kosuke; Chikazawa, Yoshitaka; Okazaki, Hitoshi*; Hayashi, Masateru*
no journal, ,
FFD-DN (failed fuel detection system by delayed neutron monitoring) method is to measure the delayed neutron flux which is released from failed fuel to sodium coolant when fuel failure occurs. Here, the part of FFD-DN method will be cleared. Then, reactor trip before fuel failure propagation could be performed by new FFD-DN detection form with B
C filter and collimator.
Takano, Kazuya; Kato, Atsushi; Uchita, Masato*; Okazaki, Hitoshi*; Ikari, Risako*
no journal, ,
Primary Heat Transport System (PHTS) flow rate is the most promising signal to detect the pump/diagrid link rupture in pool type SFR. The electromagnetic flowmeter is considered to measure the PHTS flow rate and is designed to install nearby outlet of the PHTS circulation pump in the current design of pool-type SFR with 600 MWe. The flowmeter could be significantly affected by the noise from pump motor. In order to improve the signal strength, the structure of flowmeter is drastically modified with the D-shape yokes and the magnetic circuits above and below an electrode.
