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; Sato, Wakaei*;
JNC TN9400 2000-037, 87 Pages, 2000/03
JNC-TN9400-2000-037.pdf:3.48MB
ln order to compare the nuclear characteristics of water-cooled bleeder cores with that of LMFBR, MOX fuel cell models are established for boiling and non-boiling LWR, non-boiling HWR and sodium-cooled reactor. Frst, the comarison is made between the heterogeneous cell calculation results by SRAC and those by SLAROM. The results show some differences as for neutron energy spectrum, one-grouped cross section and conversion ratio due to the different grouped cross section library (both are based on JENDL-3.2, though) used for each code, however, the difference is acceptably small for grasping the basic characteristics of the above-mentioned cores. Second, using the SLAROM code, main core parameters such as mean neutron energy, ratio of fast neutron and 
-value, are analyzed. The comparison between the cores show that softened neutron spectrum by the scattering effect of hydrogen or heavy hydrogen increase the contribution of nuclear reaction (especially for neutron capture reaction rather than fission reaction) in lower energy region comparing with LMFBR. ln order to overcome the effect, tighter lattice than LMFBR is necessary for water-cooled cores to realize the breeding of fissile nuclides. Third, effects of Pu isotopic composition on the breeding ratio are evaluated using SRAC burnup calculation. From the results, it is confirmed that degraded Pu (larger ratio of Pu-240) show the larger breeding ratio. At last, sensitivity analyses are made for k-effective and main reaction ratios. As for k-effective, using a temporary covariance data of JENDL-3.2, uncertainty resulting from the cross sections' error is analyzed for a boiling LWR and a sodium-cooled reactor. The boiling LWR core shows larger sensitivity in lower energy region than the sodium-cooled reactor (especially for the energy region lower than 1kev), And, 18-group analysis that is considered acceptably good for LMFBR analysis, should not be enough for accurate sensitivity estimation of ...
Sakurai, Takeshi; *; *; *
Journal of the Physical Society of Japan, 36(8), p.661 - 670, 1999/08
no abstracts in English
U capture to 
Pu fission rate ratios and U capture to 
U fission rate ratios at fast critical assemblySakurai, Takeshi;
JAERI-Research 95-054, 36 Pages, 1995/08
JAERI-Research-95-054.pdf:1.41MB
no abstracts in English
Yoshida, Hiroshi; Naruse, Yuji; Yamaoka, Mitsuaki*; *; *; *
JAERI-M 92-088, 105 Pages, 1992/06
no abstracts in English
;
JAERI-M 83-188, 61 Pages, 1983/11
no abstracts in English
; Kaetsu, Isao
Appl.Biochem.Biotechnol., 8, p.505 - 513, 1983/00
Times Cited Count：5 Percentile：21.94(Biochemistry & Molecular Biology)no abstracts in English
; ; *
JAERI-M 82-182, 111 Pages, 1982/12
no abstracts in English
; ; *; *; *; *
JAERI-M 9544, 174 Pages, 1981/07
no abstracts in English
JAERI-M 6728, 52 Pages, 1976/10
no abstracts in English
Tasaki, Yudai; Yamaji, Akifumi*; Amaya, Masaki
no journal, ,
In breeding core designs with light water, tight lattice fuel bundle design in which the coolant flow area is small is adopted to prevent the neutron moderating. Additionally, the core often consists of MOX fuel and blanket fuel, which aims to irradiate depleted uranium effectively. In preceding study, the concept of "Multi-axial fuel shuffling" has been proposed for a higher breeding core design of supercritical-water cooled reactor (SCWR), in which the core consists of multiple layers of MOX fuels and blanket fuels with independent fuel shuffling for the upper blanket layer where coolant density is lowest. As a result, the SCWR with multi-axial fuel shuffling has shown improvement of breeding performance. The same principle may be applied to BWR, since the coolant density gets low due to developing void fraction. However, the fuel rod included such a core design has two kinds of fuel pellets, and MOX fuel parts tend to get high power peaking. Therefore, it is necessary to investigate and mitigate the fuel maximum temperature and the shear stress of the boundary between MOX and blanket fuel parts which may occur by the difference of PCMI characteristics of two fuel parts. Moreover, it is possible that the cladding outer diameter change especially in MOX fuel parts may impact on the thermal-hydraulics, because the gap between rods is narrow owing to the tight lattice fuel bundle design. This study has shown the improvement of breeding performance of BWR with multi-axial fuel shuffling, and the fuel design which mitigates the above design issues. The cladding outer diameter change doesn't impact on critical heat flux ratio mostly, but depends on pressure drop of the flow channel. Therefore, this result suggests a design issue with respect to the core flow distribution.
