Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Matsuura, Makoto; Hatori, Masakazu; Ikeda, Makinori
Nuclear Engineering and Design, 237(12-13), p.1419 - 1428, 2007/07
Times Cited Count：19 Percentile：75.80(Nuclear Science & Technology)MONJU is a prototype Fast Breeder Reactor (FBR) in Japan. The sodium-water reaction in the steam generator (SG) is one of the important safety assessment items for a sodium cooled reactor like MONJU. A latest evaluation method on the design margin against the overheating tube rupture showed that it had not enough margins on the present SG system in the worst case. For improving that margin, it needs to shorten the time of the sodium-water reaction by earlier water leak detection in the SG and sooner water ejection from the SG tubes. Therefore MONJU is now carrying out the following modification works (1) addition of steam relief valves, (2) addition of a gas pressure gauge with changing the interlock logic and lowering the trigger level, (3) reducing the opening of the valves on the SG gas flow line to the dump tank because of earlier detection for the pressure rise. After this modification, the design margin of the SG system will be sufficiently improved. For the tube materials, the value of the cumulative damage for the creep failure will be much smaller than 1, and the equivalent stress for the ductile failure will be much smaller than the tensile strength.
Okabe, Ayao; Onuki, Koji; Kikuchi, H.; M.Uchihashi; Nishibayashi, Yohei; Ikeda, Makinori; Miyake, Osamu
JNC TN2400 2003-005, 62 Pages, 2004/03
JNC-TN2400-2003-005.pdf:2.41MB
Sodium combustion analyses were performed using ASSCOPS version 2.1 in order to obtain background data for evaluating validity of the mitigation system against secondary sodium leak of MONJU. The analytical results of floor temperature and hydrogen concentration were summarized in this report.In the sodium combustion analyses under the detailed design conditions, it was confirmed that the temperature rise of the floor liner was reduced In addition, as for the hydrogen concentration in sodium leak process which is formed by the reaction of sodium and moisture, it was confirmed that it is restricted under 4% of the hydrogen burn criterion. Concerning the hydrogen concentration due to the reaction with sodium and sodium hydroxide in the sodium pool after the storing, in the same way, it was confirmed that it is restricted under 4% of the criterion.
Imo, Kazumichi; Onuki, Koji; Kikuchi, H.; Morishita, Masaki; Igawa, Kenichi*; Nishibayashi, Yohei; Ikeda, Makinori
JNC TN2400 2003-004, 78 Pages, 2004/03
JNC-TN2400-2003-004.pdf:4.74MB
About the secondary system floor liner of Monju, the mechanical soundness of a floor liner to the thermal load conditions by combustion of leak sodium was evaluated by large displacement inelastic analysis and the partial structure model test.In large displacement inelastic analysis, it was confirmed that heat strain of a floor liner was less than the standard value of the strain for no through-wall crack. In addition, the influence evaluation by a temperature increasing rate, liner board thickness, and the existence of corrosion thinning was performed. The result, the influence on the maximum strain was small in any parameter.In the partial structure model test, even when a strain more excessive than the standard value of strain was given, it was confirmed no through-wall crack in a liner plate.In addition, this report improves the evaluation conditions of the conventional research report [1], and resummarizes them to detailed design evaluation.
Ikeda, Makinori; ; ; ; Otaka, Masahiko
Proceedings of 3rd International Conference on Nuclear Engineering (ICONE-3), (3), 1659 Pages, 1995/00
None
Ikeda, Makinori
Proceedings of 22nd DOE/NRC Nuclear Air Cleaning Conference, p.791 - 807, 1993/07
None
Shimada, Koji; Tateishi, Ryo*; Ishimaru, Tsuneari; Sasaki, Akimichi; Tanaka, Yukumo; Miyazaki, Masashi; Yasue, Kenichi; Niwa, Masakazu; Sueoka, Shigeru; Umeda, Koji; et al.
no journal, ,
Activity evaluation of crush zones encountered in basement rock is an issue of the seismic safety assessment of nuclear plant and geological isolation of radioactive wastes. The selection of crush zone of which has been evaluated should be defined as the latest one by means of turn determination of crush zone activity based on stratigraphic or structural geological method. A lesson from granitic basement rock (Kojaku granite) holding the fast breeder reactor "Monju" is presented. The Kojaku Granite form the oval Tsuruga peninsula (ca. 8km in width) on the southeastern coast of the Sea of Japan and the age is 68.5 plus/minus 0.7Ma (Zircon U-Pb age).1. Stratigraphy-oriented turn determination of crush zone activity. (1.1) Turn determination using cover sediments. (1.2) Turn determination using dyke, mineral and clay vein. 2. Structural-oriented turn determination of crush zone activity.
Ito, Kazumoto; Maeda, Hiroshi; Ikeda, Makinori
no journal, ,
no abstracts in English
Yoshimura, Kazuo; Ikeda, Makinori; Enuma, Yasuhiro; Aizawa, Kosuke
no journal, ,
JAEA has conducted a safety evaluation of impacts of double leakage at the PHTSs considering the passive safety features of Monju as the best-estimate evaluation for a DEC. The result shows that the total amount of leaked sodium can be reduced by the depressurization of the cover gas resulting from decrease in coolant inventory, i.e. negative pressure effects. The reactor coolant level required for decay heat removal, therefore, can be maintained even under double leakage at the PHTSs.
Ishimaru, Tsuneari; Shimada, Koji; Sasaki, Akimichi; Tanaka, Yukumo; Miyazaki, Masashi; Yasue, Kenichi; Niwa, Masakazu; Sueoka, Shigeru; Umeda, Koji; Ikeda, Makinori
no journal, ,
The Nuclear Regulation Authority instructed to develop a further additional research plan regarding the crushed zones on the Monju site against the JAEA on September 25. The JAEA developed a research plan in response to this instruction, and, the stripping investigation with expansion of the area, the additional detailed geographical and geological surveys around the mountains/terrace boundary, and the marine seismic surveys in the coastal waters, were conducted. The fracture zones were grouped into 2 systems called 
-system and 
-system in the on-site investigation. We examined the cross-cutting relationships and displacements of the fracture zones and confirmed that the -system was formed after the -system. From the investigation results so far, similar to the results of the compilation report of April 31, 2010, no clear evidence was observed to support that on-site crushed zones are active faults.
Fukano, Yoshitaka; Futagami, Satoshi; Enuma, Yasuhiro; Suzuki, Takayuki; Nakai, Ryodai; Ikeda, Makinori
no journal, ,
no abstracts in English
Ohara, Takaharu; Ikeda, Makinori; Morishita, Masaki; Miyazaki, Masashi; Shimada, Koji; Moriizumi, Makoto*
no journal, ,
no abstracts in English
Ishimaru, Tsuneari; Shimada, Koji; Niwa, Masakazu; Yasue, Kenichi; Tateishi, Ryo*; Ikeda, Makinori; Umeda, Koji
no journal, ,
no abstracts in English
Ito, Kazumoto; Maeda, Hiroshi; Ikeda, Makinori
no journal, ,
no abstracts in English
