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Sukegawa, Atsuhiko; Kawasaki, Hiromitsu*; Okuno, Koichi*
Progress in Nuclear Science and Technology (Internet), 2, p.375 - 381, 2011/10
A complete 3D neutrons and photons transport analysis by Monte Carlo transport code system PHITS (Particle and Heavy Ion Transport code System) have been performed for superconducting tokamak fusion device such as JT-60 Super Advanced (JT-60SA). It is possible to make use of PHITS in the port streaming analysis around the devices for the tokamak fusion device, the duct streaming analysis in the building where the device is installed, and the sky shine analysis for the site boundary. The neutron transport analysis by PHITS makes it clear that the shielding performance of the superconducting tokamak fusion device with the cryostat is improved by the graphical results. From the standpoint of the port streaming and the duct streaming, it is necessary to calculate by 3D codes for the neutronics analysis of superconducting tokamak fusion device.
Sukegawa, Atsuhiko; Okuno, Koichi*; Kawasaki, Hiromitsu*
RIST News, (51), p.20 - 29, 2011/07
no abstracts in English
Sukegawa, Atsuhiko; Takiyoshi, Koji*; Amano, Toshio*; Kawasaki, Hiromitsu*; Okuno, Koichi*
Progress in Nuclear Science and Technology (Internet), 1, p.36 - 39, 2011/02
A complete 3D radiation shielding analysis by PHITS has been performed for the JT-60U and JT-60 superconducting tokamak device (JT-60SA) in the present study. The PHITS has been developed for high energy particles physics in Japan. The neutron and photon transport analysis less than 20 MeV with the general cross section library is the same algorism of MCNP-4C code. The monoenergetic neutron (E = 2.45 MeV) of the DD fusion devices are used for the neutron source in the analysis. The neutron source distribution are available a toroidally symmetric source for the analysis. The toroidal source has a poloidal distribution, so that a source routine in the PHITS has been replaced a newly developed source routine. The visual nuclear responses such as the neutron flux distribution, the photon flux distribution, the nuclear heating of the coils and the dose rate around the devices has been calculated by the PHITS for the fusion tokamak devices. Initial results by the PHITS have been demonstrated.
Okuno, Hiroshi; Sato, Shohei; Kawasaki, Hiromitsu*
Journal of Nuclear Science and Technology, 46(12), p.1137 - 1144, 2009/12
Times Cited Count:3 Percentile:23.90(Nuclear Science & Technology)The critical concentrations of metal-SiO and -H
O mixtures were calculated for 26 actinides including
U,
Pu,
Am,
Cm and
Cf, where the critical concentration was defined as the concentration that the infinite neutron multiplication factor, k
being calculated to be 1.0. The calculations were performed using the Monte Carlo neutron transport calculation code MCNP5 combined with the evaluated nuclear data library JENDL3.3. The results showed that the critical actinide concentration of metal-SiO
was ca. 1/5 of that of metal-H
O for all the fissile nuclides investigated. The k
's of the metal-SiO
and metal-H
O at a half of the respective critical actinide concentration, which concentration was assumed as the subcritical actinide concentration limit, were found to be less than 0.8 for all the actinides considered. Applying a sum-of-fractions rule with respect to the ratios of actinide concentration to the subcritical actinide concentration limit for six fissile nuclides, subcriticality of high-level radioactive wastes was confirmed for a reported sample. The effect of different nuclear data libraries on the results of critical actinide concentrations was found large for
Cm,
Cm and
Cf.
Yamauchi, Michinori; Nishitani, Takeo; Nishio, Satoshi; Hori, Junichi*; Kawasaki, Hiromitsu*
Fusion Science and Technology, 52(4), p.781 - 785, 2007/11
Times Cited Count:0 Percentile:0.00(Nuclear Science & Technology)Low activation material is one of the important factors for constructing high power fusion reactors in future. Unexpected activation, however, may be produced through sequential reactions due to charged particles created by primary neutron reactions. In the present work, the effect of the sequential activation reaction was studied for candidate low activation materials of a fusion demo-reactor. The calculations were conducted by the ACT4 code developed in JAEA for the activation analysis of fusion reactor designs and revised for dealing with the sequential activation reactions. The results say that the real dose rate around vanadium alloy which may be used as structural material becomes larger after the cooling for 3 years by considering the reaction. Although metal hydrate is regarded as an excellent low activation shield material, the reactions due to recoil protons are influential and the dose rate around vanadium hydrate is several orders of magnitude larger than the value calculated without the sequential process after 2 weeks cooling. In case of liquid breeders, the effect of sequential reactions is popularly observed and it affects the shield design of circulation loop.
Yamauchi, Michinori; Hori, Junichi*; Sato, Satoshi; Nishitani, Takeo; Konno, Chikara; Kawasaki, Hiromitsu*
JAEA-Data/Code 2007-016, 58 Pages, 2007/09
The ACT-XN is a revised version of the ACT4 code, which was developed in the Japan Atomic Energy Agency (JAEA) to calculate the transmutation, induced activity, decay heat, delayed -ray source etc. for fusion devices. The ACT4 code has not dealt with the sequential reactions of charged particles generated by primary neutron reactions. However, the reactions cannot be disregarded in the design employing low activation material, and the code was newly supplemented with the function to calculate the activation for sequential reactions and renamed the ACT-XN. The FISPACT data were adopted for (x,n) reaction cross sections, charged particles emission spectra and stopping powers. An application of the code to the analysis of FNS experiment for LiF activation confirmed that the function is enough reliable, and a notice was presented through the design calculation of the Demo-reactor with FLiBe that the dose rate may be enhanced by sequential reactions.
Yamauchi, Michinori*; Hori, Junichi*; Ochiai, Kentaro; Sato, Satoshi; Nishitani, Takeo; Kawasaki, Hiromitsu*
Fusion Engineering and Design, 81(8-14), p.1577 - 1582, 2006/02
Times Cited Count:1 Percentile:9.73(Nuclear Science & Technology)no abstracts in English
Yamauchi, Michinori*; Sato, Satoshi; Nishitani, Takeo; Kawasaki, Hiromitsu*
Proceedings of 21st IEEE/NPSS Symposium on Fusion Engineering (SOFE 2005) (CD-ROM), 4 Pages, 2005/09
no abstracts in English
Nakagawa, Tsuneo; Kawasaki, Hiromitsu*; Shibata, Keiichi
JAERI-Data/Code 2002-020, 327 Pages, 2002/11
no abstracts in English
Okuno, Hiroshi; Kawasaki, Hiromitsu*
Journal of Nuclear Science and Technology, 39(10), p.1072 - 1085, 2002/10
Times Cited Count:2 Percentile:16.45(Nuclear Science & Technology)Critical and subcritical masses were calculated for a sphere of five curium isotopes from 243Cm to 247Cm, in metal and in metal-water mixtures, considering three reflector conditions: bare, with a water reflector or a stainless steel reflector. The calculation were made mainly with a combination of a continuous energy Monte Carlo neutron transport calculation code, MCNP, and the Japanese Evaluated Nuclear Data Library, JENDL-3.2. Other evaluated nuclear data files, ENDF/B-VI and JEF-2.2, were also applied to find differences in calculation results of the neutron multiplication factor originated from different nuclear data files. A large dependence on the evaluated nuclear data files was found in the calculation results.
Okuno, Hiroshi; Kawasaki, Hiromitsu*
JAERI-Research 2000-040, 44 Pages, 2000/09
no abstracts in English
Sugi, Teruo*; Nakagawa, Tsuneo; Kawasaki, Hiromitsu*;
JAERI-Data/Code 99-039, 52 Pages, 1999/08
no abstracts in English
Suyama, Kenya; Komuro, Yuichi; Takada, Tomoyuki*; Kawasaki, Hiromitsu*; Ouchi, Keisuke*
JAERI-Data/Code 98-004, 172 Pages, 1998/02
no abstracts in English
Okuno, Hiroshi; Sato, Shohei; Kawasaki, Hiromitsu*
no journal, ,
The critical masses of 23 minor actinides in metal and 7 minor actinides in metal-water mixtures were calculated using a combination of the Monte Carlo neutron transport code MCNP4C2 and the nuclear data library JENDL-3.3. The selected reflector conditions were bare, with a 30-cm-thick water and with a 30-cm-thick SS304. Comparisons of the calculated critical masses with the data in reference literature and those calculated using JENDL-3.2 were made. The effect of reflectors on the critical masses and the relations between the critical mass of actinide in metal and its neutron multiplication factor in the infinite media were discussed.
Yamauchi, Michinori; Hori, Junichi*; Nishitani, Takeo; Sato, Satoshi; Ochiai, Kentaro; Kawasaki, Hiromitsu*
no journal, ,
no abstracts in English
Sukegawa, Atsuhiko; Konno, Chikara; Sato, Satoshi; Kawasaki, Hiromitsu*; Miya, Naoyuki
no journal, ,
no abstracts in English
Yamauchi, Michinori; Hori, Junichi*; Nishitani, Takeo; Ochiai, Kentaro; Sato, Satoshi; Kawasaki, Hiromitsu*
no journal, ,
no abstracts in English
Okuno, Koichi*; Sukegawa, Atsuhiko; Kawasaki, Hiromitsu*
no journal, ,
no abstracts in English
Okuno, Hiroshi; Tonoike, Kotaro; Kawasaki, Hiromitsu*
no journal, ,
no abstracts in English
Sukegawa, Atsuhiko; Miya, Naoyuki; Kawasaki, Hiromitsu*
no journal, ,
no abstracts in English