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Porter, G. D.*; Rognlien, T. D.*; Rensink, M. E.*; Loarte, A.*; Asakura, Nobuyuki; Takenaga, Hidenobu; Matthews, G.*; Contributors to JET-EFDA Workprogramme*
Journal of Nuclear Materials, 313-316, p.1085 - 1088, 2003/03
Times Cited Count：24 Percentile：81.03(Materials Science, Multidisciplinary)no abstracts in English
Department of Fuel Cycle Safety Research
JAERI-Review 2001-038, 600 Pages, 2001/12
JAERI-Review-2001-038.pdf:19.64MB
no abstracts in English
Takanashi, Mitsuhiro; ; Aoshima, Atsushi
JNC TN8400 2001-022, 60 Pages, 2001/03
JNC-TN8400-2001-022.pdf:1.31MB
A numerical simulation code for the TRUEX (Transuranium Extraction) process was developed. Concentration profiles of americium and europium were calculated for some experiments of the counter current extraction system those were carried out in CPF (Chemical Processing Facility) by using the code. Calculation profiles were in agreement with the experimental results. Operational conditions were also examinted for the americium recovery experiment by the TRUEX process carried out in the Plutonium Fuel Center. It was shown that lowering the concentration of nitric acid in the scrub solution and decreasing the flow rate of solvent and strip solution was effective for improving the performance of the stripping step and reducing the volume of the waste solution. In order to find the optimum conditions for various experiments, this simulation code was modified to calculate the concentration profiles of other metal elements such as zirconium and iron and the effect of oxalic acid on the extraction behavior of the metal elements. The calculated concentration profiles of americium and europium were varied by this modification. In the experiment at CPF, the calculations were carried out to obtain recovery ratio of americium in the product stream with the amount of oxalic acid added to the process. This calculation result showed that it was possible to improve the performance of decontamination of fission products by increasing oxalic acid concentration added to the process. The calculation was also carried out for finding the optimum conditions of oxalic acid concentration added to the europium recovery process.
JNC TN9400 2000-008, 323 Pages, 2000/02
JNC-TN9400-2000-008.pdf:25.2MB
This rport presents numerical results on theemal striping characteristics at a tee junction of LMFBR coolant pipe, carried out using a direct numerical simulation code DINUS-3. In the numerical investigations, it was considered a tee junction system consisted of a main pipe (1.33 cm
) with a 90
elbow and a branch pipe, and four parameters, j.e., (1)diameter ratio 
between both the pipes, (2)flow velocity ratio 
between both the pipes, (3)angle 
between both the pipes, and (4)Reynolds number Re. From the numerical investigations, the following characteristics were obtained: (1)According to the decreasing of the diameter ratio, significant area of second-order moments was expanded in the fixed condition of =1.0. (2)Significant second-order moments area was expanded for the increasing of the flow velocity ratio specified by varying of the main pipe velocity in the case of a = 1.0 constant condition. 0n the other hand, the area was expanded for the decreasing of the velocity ratio defined by varying of the branch pipe velocity in the case of a = 3.0 constant condition. (3)Maximum second-order moments values were generated in the case of = 180 due to the influence of interactions between main pipe flows and jet flows from the branch pipe. (4)According to the increase of Reynolds number, significant area of second-order moments was expanded due to the activation of turbulence mixing in the main pipe.
PNC TN9410 98-044, 47 Pages, 1998/06
Thermal striping phenomena characterized by stationary random temperature fluctuations are observed in the region immediately above the core exit of liquid-metal-cooled fast breeder reactors (LMFBRs) due to the interactions of cold sodium flowing out of a control rod (C/R) assembly and hot sodium flowing out of adjacent fuel assemblies (F/As). Therefore the in-vessel components located in the core outlet region, such as upper core structure (UCS), flow guide tube, C/R upper guide tube, etc., must be protected against the stationary random thermal process which might induce high-cycle fatigue. In this study, thermal striping conditions at the tee junction in the MONJU EVST system (maximum temperature difference : 110 C, Velocity ratio between main and branch pipes : 0.25) were investigated numerically by the use of computer programs. From the investigations, the following results have been obtained: (1) Effects of the secondaly flows generated by the existence of 90 elbow located at upstream position of the tee junction were negligeble, because the flow velocity in the main pipe is 0.25 of the flow velocity in the branch pipe. (2) A ration between maximum and effective amplitudes of the temperature fluctuations calculated by the DINUS-3 code was 3.18. It was concluded that the value 6.0 as the ratio used in the integrity evaluation of the EVST system is a coservative side. (3) There was a limit in ability of a time-averaged multi-dimensional code AQUA, in the evaluation of thermal striping phenomena with recirculation flows. One of the reasons was considered that the local equilibrium of turbulence flows was not established in this tee junction problem.
Homma, Shunji*; Tajima, Yasunori*; Koga, Jiro*; Matsumoto, Shiro*
PNC TJ1609 97-001, 47 Pages, 1997/02
no abstracts in English
Asakura, Nobuyuki; Hoshino, Kazuo; Uto, Hiroyasu; Someya, Yoji; Shimizu, Katsuhiro; Shinya, Kichiro*; Tokunaga, Shinsuke; Tobita, Kenji; Ono, Noriyasu*
no journal, ,
no abstracts in English
Sato, Yuji; Shirahama, Takuma*; Ishibashi, Junichi*; Muramatsu, Toshiharu
no journal, ,
no abstracts in English
