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Lee, S.; Kondoh, Takashi; Miura, Yukitoshi
Japanese Journal of Applied Physics, Part 1, 41(11A), p.6574 - 6576, 2002/11
Times Cited Count:1 Percentile:5.6(Physics, Applied)no abstracts in English
Chiba, Shinichi; Kawano, Yasunori; Tsuchiya, Katsuhiko; Inoue, Akira*
JAERI-Research 2001-050, 59 Pages, 2001/11
no abstracts in English
Lee, S.; Kondoh, Takashi; Miura, Yukitoshi
Purazuma, Kaku Yugo Gakkai-Shi, 77(9), p.919 - 929, 2001/09
no abstracts in English
Lee, S.; Kondoh, Takashi; Yonemoto, Y.*; Miura, Yukitoshi
Review of Scientific Instruments, 71(12), p.4445 - 4448, 2000/12
Times Cited Count:6 Percentile:44.18(Instruments & Instrumentation)no abstracts in English
; ; *; Yamaguchi, Akira
JNC TN9400 2000-109, 96 Pages, 2000/11
Numerical calculations were carried out for a free surface sloshing, a thermal stratification, a thermal striping, and a natural convection as key phenomena of in-vessel thermohydraulics in future fast reactor systems with various fluids as coolants. This numerical work was initiaied based on a recognition that the fundamental characteristics of the phenomena have been unsolved quantitatively in the use of various coolants. From the analysis for the phenomena, the following results were obtained. [Free Surface Sloshing phenomena] (1)Ther is no remarkable difference betweeen liquid sodium and luquid Pb-Bi in characteristics of internal flows and free surface charatristics based on Fr number. (2)the AQUA-VOF code has a potentiall enough to evaluate gas entrainment behavior from the free surface including the internal flow characteristics. [thermal Stratification Phenomena] (1)On-set position of thermal entainment process due to dynamic vortex flows was moved to downstream direction with decreasing of Ri number. 0n the other hand, the position in the case of C0 gas was shifted to upstream side with decreasing of Ri number. (2)Destruction speed of the thermal stratyification interface was dependent on thermal diffusivity as fluid properties. therefor it was concluded that an elimination method is necessary for the interface generated in C0 gas. [thermal Striping Phenomena] (1)Large amplitudes of fluid temperature fluctuations was reached to down stream area in the use of CO gas, due to larger fluid viscosity and smaller thermal diffusivity, compared with liquid sodium and liquid Pb-Bi cases. (2)To simulate thermal striping conditions such as amplitude and frequency of the fluid temperature fluctuations, it isnecessary for coincidences of Re number for the amplitude and of velocity value for the frequency, in various coolants. [Natural Convection Phenomena] (1)Fundamental behavior of the natural convection in various coolant follows buoyant jet ....
Lee, S.; Kondoh, Takashi
Review of Scientific Instruments, 71(10), p.3718 - 3722, 2000/10
Times Cited Count:4 Percentile:36.74(Instruments & Instrumentation)no abstracts in English
; Yamaguchi, Akira
JNC TN9400 2000-056, 150 Pages, 2000/05
[Purpose] The work was performed to make clear thermal-hydraulic issues resulting in the use of various coolants for fast reactors. [Method] Plant design features due to a use of working fluid other than sodium and design concepts relating a simplification of safety related systems were investigated. And based on the results, quantitative evaluation was made on the topical themal-hydraulic issues. Then both thermal stratification and striping phenomena were evaluated by the used of thermo-hydraulics computer programs. [Results] (1)Thermal-hydraulic issues Topical thermal-hydraulic issues of gaseous and heavy metal cooled reactors were extracted. (a)Gas cooled reactors : natural circulation,flow-induced vibration, depressurization accident (b)Heavy metal cooled reactors : thermal stratification, flow-induced vibration, sloshing And also the thermal-hydraulic issues relating compact reactor assembly and RVACS were extracted resulting from a simplification of safety related systems. (2)Evaluation of thermal stratification and striping phenomena. The following order of affects for the phenomena was obtained: (a) Thermal stratification: CO Sodium Lead, (b) Thermal Striping: CO Lead Sodium
; ; Mizuta, Shunji
JNC TN9400 2000-040, 41 Pages, 2000/03
The corrosion behavior of ferritic stainless steels applied to core components under C0 gas environment was investigated in order to be helpful to fuel design in C0 gas cooled reactor as the feasibility study for fast breeder reactor. The dependence of the corrosion behavior, before a breakaway occurs, on C0 gas temperature, Si and Cr contents of ferritic steels was determined quantitatively. The following correlations to calculate the metal loss thickness was established. X = 4.4w w = √(kt) k = exp( - 5.45[Si]) exp( - 1.09[Cr]) exp( - 11253/T) = 1.65 104.40 10 X : metal loss thickness[ml, w : corrosion weight gain [mg/cm] k : parabola constant [(mg/cm)/hr], t : time [hr], : constant [Si] : Si content[wt.%], [Cr] : Cr content [wt.%], T : temperature [K]
Mizuta, Shunji; ;
JNC TN9400 2000-032, 38 Pages, 2000/03
lt is necessary for feasibility study of fast reactor to evaluate the oxidation of the austenitic stainless steels in the case of using for core material in carbon dioxide gas-cooled reactor. The properties for oxidation of austenitic stainless steels in carbon dioxide were surveyed in literatures and the data were selected after evaluation of factors for oxidation in carbon dioxide. The equation of oxidation in carbon dioxide for PE16, 20Cr/25Ni/Nb, 18Cr-8Ni and JNC Cladding materials were proposed. The equation for oxidation of austenitic stainless steels were expressed as upper limit for the equation according to parabolic law. The equation for JNC cladding materials (PNC316, PNC1520, 14Cr-25Ni) was proposed based the oxidation behavior of 18Cr-8Ni which is same oxidation region for weight gain in three-component system of Fe-Cr-Ni, in addition to evaluate of effect for silicon content. The oxidation equation of 20Cr/25Ni/Nb was applied to the high Ni alloy of JNC cladding material. The obtained equation is as follows, X = 4.4W1000, W = , kp = exp(-Q/(RT)), X: oxide thickness[m], W : weight gain[gcm], kp : parabolic rate constant[gcm s], t :time[sec] : constant[gcmS], Q : activation energy[J・mol], R : gas constant[8.314J K mol], T : temperature[K] (1) PE16 : kp = 1.09010 exp(-192,500/(RD)), (2) 20Cr/25Ni/Nb : kp = 1.65110 exp(-201,300/(RT)) High Ni alloy (JNC), (3)18Cr-8Ni : kp = 1.50310 exp(-60,000/(RT)), (4) PNC316, PNC1520 : kp = 1.50310 exp(-60,000/(RT))0.62 14Cr-25Ni(JNC) The weight gain is (3)(4)(2)(1) in order.
Yang Zumao*;
JNC TN9400 2000-009, 81 Pages, 2000/02
It is important to study thermal stratification and striping phenomena for they can induce thermal fatigue failure of structures. This presentation uses the AQUA code, which has been developed in Japan Nuclear Cycle Development Institute (JNC), to investigate the characteristics of these thermal phenomena in water, liquid sodium, liquid lead and carbon dioxide gas. There are altogether eight calculated cases with same Richardson number and initial inlet hot velocity in thermal stratification calculations, in which four cases have same velocity difference between inlet hot and cold fluid, the other four cases with same temperature difference. The calculated results show : (1) The fluid's properties and initial conditions have considerable effects on thermal stratification, which is decided by the combination of such as thermal conduction, viscous dissipation and buoyant force, etc., and (2) The gas has distinctive thermal stratification characteristics from those of liquid because for
Kawano, Yasunori; Chiba, Shinichi; Inoue, Akira*
Journal of Plasma and Fusion Research SERIES, Vol.3, p.397 - 401, 2000/00
no abstracts in English
Kawano, Yasunori; Chiba, Shinichi; Shirai, Hiroshi; *; Nagashima, Akira
Review of Scientific Instruments, 70(2), p.1430 - 1434, 1999/02
Times Cited Count:11 Percentile:61.16(Instruments & Instrumentation)no abstracts in English
Shimizu, Yuichi
Radioisotopes, 43(3), p.147 - 156, 1994/03
no abstracts in English
Sugimoto, Shunichi*; Shimizu, Yuichi; Suzuki, Nobutake
Chem. Express, 8(7), p.451 - 454, 1993/00
no abstracts in English
Kawano, Yasunori; Nagashima, Akira; Ishida, Shinichi; Fukuda, Takeshi; Matoba, Toru
Review of Scientific Instruments, 63(10), p.4971 - 4973, 1992/10
Times Cited Count:19 Percentile:82.91(Instruments & Instrumentation)no abstracts in English