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Fujita, Shunya*; Abe, Yutaka*; Kaneko, Akiko*; Chonan, Fuminori*; Yuasa, Tomohisa*; Yamaki, Tatsunori*; Segawa, Tomoomi; Yamada, Yoshikazu
Proceedings of 25th International Conference on Nuclear Engineering (ICONE-25) (CD-ROM), 8 Pages, 2017/07
From the observation results, in the process of flushing, the behaviors leading to flushing were classified divided into three types. First type is that first generation bubble from heating leads to flushing. Second type is that nucleate boiling continues during heating and stop, finally single bubble generates and leads to flushing. Third type is defined that gradual evaporation occurs without bubbles. It was revealed that the total quantities of heat released by flushing are approximately equal when assuming the flushing mechanism, it can be triggered that a large amount of micro bubbles are instantaneously generated and grew.
Konishi, Satoshi
Fusion Engineering and Design, 58-59, p.1103 - 1107, 2001/11
Times Cited Count:6 Percentile:44.09(Nuclear Science & Technology)no abstracts in English
Ikeda, Yoshitaka
JAERI-Research 99-061, p.46 - 0, 1999/12
no abstracts in English
Miura, Akihiko;
JNC TN8410 99-044, 189 Pages, 1999/10
This report includes several results that were made by calculation with several methods to clarify the cause of the fire and explosion incident. In the early times, we didn't have exact information of chemicaI property, reaction rate and any physical constants that we needed. But because the only data that indicate the cooling process of bituminized product was reported, we made heat-transporting calculation with taking this data. Based on the theory of the thermal hazard evaluation that was called Semenov theory or Frank-Kamenetskii theory, the amount of heat generation was estimated using the heat transporting calculation. Common theories were introduced in first section. In the second section, several results of heat transporting calculation were indicated. Calculations were made as follows. First, the model of bituminized product that was filled in the drum was created with the data of cooling process. Second, when the heat was generated in the drum, time-dependent temperature distribution was calculated. And last, judging from the balance of heat generation and heat radiation the critical heat rate was estimated.
; *; Yoshida, Eiichi; Aoto, Kazumi
JNC TN9400 2000-011, 33 Pages, 1999/03
The damage was observed in rupture disk for the A-loop superheater of sodium-water reaction products releasing system for MONJU on March 3, 1998. Low temperature creep and stress corrosion cracking tests were carried out as the causes investigation of the damage. As the result, the followings are clarified. (1)The possibility that low temperature creep is the principal damage is small. (2)The stress corrosion cracking under NaOH environment due to the reaction of Na vapor and moisture condensed on the surface of glass beads as remains is the most probable cause on the damage. (3)Comparatively many glass beads remained in damaged surface. The gap between rupture disk and vacuum support was narrower than other parts, and they were not directly exposed to the Na vapor for a long time. The above factors caused the perfect intergranular cracking by stress corrosion. Since NaOH was chemically changed into the harmless NaO on the location except for damaged zone by full Na vapor, the stress corrosion cracking was not generated.
Shiotsu, Masahiro*; Hata, Koichi*; *; Shirai, Yasuyuki*; *; Sakai, Takaaki
PNC TY9604 97-002, 15 Pages, 1997/03
no abstracts in English
*; *; *; *; *; *; *
PNC TJ9164 94-006, 133 Pages, 1994/03
This report gives an applicability of SWAT-3 facility and contents of the reconstruction in order to confirm a DBL (Design Basis Leak) for the demonstration reactor SG. (1).Test Cndition and test case. Evaluation of the wall temperature for adjacent heat transfer tubes under the sodium-water reaction event was performed. (a)As the effect of tube rupture due to overheating, failure of upper part of the helical coil was severer than one of the lower part. (b)The wall temperature depends on the water side condition. (c)Reference test condition, whici is water leak rale about 1 kg/s, failure of upper part of the helical coil and 30% partial load, was selected. A total of ten test cases were decided. (2).System and Components Design. (a)Large leak sodium-water reaction analyses including water injection rate analysis and quasi-steady pressure analysis were performed. The maximum water leak rate of 1 DEG was 7.2 kg/s and the water leak rate at the quasi-steady state was 3.1 kg/s. The maximum pressure was 18.1kg/cma at the piping between the reaction vessel and IHX, the pressure was within the design condition of SWAT-3 facility. (b)Based on the results of the large leak sodium-water reaction analyses, a reaction vessel, water heaters and a dump tank were designed and their design specification were clarified. The reaction vessel was a scale of one third of the demonstration reactor SG and it was designed to be able to conduct the water injection test twice with one test unit. (c)A system and piping diagram, and many kinds of list (Piping list, Valve list, instrumentlist) were made up. (3).Reconstruction scope and arrangement plan. The reconstruction scope and a layout for the components and piping were clarfied and the arrange ment plans were made up. (4)Reconstruction period. The recoastruction period and man power for the design, fabrication, inspection and installation were studied and the reconstruction schedule was made up.
Ohtaki, Akira
PNC TN9410 90-062, 145 Pages, 1990/04
It is important to control an operation to avoid water flow in which cause of SCC for a superheater which is made by astinetic stainless steel. During the superheater war㎜ing operation at the 50MW Steam Generator Test Facility, temperature fluctuation at the inlet tube sheet are easily occurred, and existence of saturated water with in warmming steam is regarded as the cause of it. A test simulating operating conditions of "Monju" superheater warmming was carried out to comfirm start up condition of "Monju". Test results show that a part of war㎜ing steam was cooled down to saturated temperature in main steam pipe which temperature is still lower than the saturated temperature, then the saturated water flows in the tube sheet which temperature is as high as sodium inlet temperature, and cause the temperature fluctuation. In order to confirm the effect of pre-heating the main pipe using trace line, a trace line was adapted at the main steam pipe, and the same superheater warmming simulation test was performed. Test results show that trace line was effective to pre-heat the main steam pipe exceeding temperature, and the temperature fluetuation was considerably decreased.
Yamamoto, Tadatoshi; ; ; Wadachi, Yoshiki
JAERI-M 84-231, 15 Pages, 1985/01
no abstracts in English
; *; ; Matsumoto, Hiroshi; ; ; ; ; ; ; et al.
JAERI-M 84-206, 22 Pages, 1984/11
no abstracts in English
; ; ; ; ; ; ;
JAERI-M 84-150, 10 Pages, 1984/09
no abstracts in English
; ; ; Matsuda, Shinzaburo; Ohara, Yoshihiro;
JAERI-M 9226, 46 Pages, 1980/12
no abstracts in English
; Kuriyama, Isamu; *; *
JAERI-M 7086, 23 Pages, 1977/05
no abstracts in English
; Sanokawa, Konomo; ; Ouchi, Mitsuo
Nihon Kikai Gakkai Rombunshu, B, 40(336), p.2311 - 2320, 1974/00
no abstracts in English