Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Fujimoto, Nozomu*; Tada, Kenichi; Ho, H. Q.; Hamamoto, Shimpei; Nagasumi, Satoru; Ishitsuka, Etsuo
Annals of Nuclear Energy, 158, p.108270_1 - 108270_8, 2021/08
Times Cited Count：3 Percentile：44.61(Nuclear Science & Technology)Okumura, Keisuke; Kawasaki, Kenji*; Mori, Takamasa
JAERI-Research 2005-018, 64 Pages, 2005/08
JAERI-Research-2005-018.pdf:3.26MB
In the KRITZ-2 critical experiments, criticality and pin power distributions were measured at room temperature and high temperature (about 245 degree C) for three different cores loading slightly enriched UO
or MOX fuels. For nuclear data testing, benchmark analysis was carried out with a continuous-energy Monte Carlo code MVP and its four nuclear data libraries based on JENDL-3.2, JENDL-3.3, JEF-2.2 and ENDF/B-VI.8. As a result, fairly good agreements with the experimental data were obtained with any libraries for the pin power distributions. However, the JENDL-3.3 and ENDF/B-VI.8 give under-prediction of criticality and too negative isothermal temperature coefficients for slightly enriched UO cores, while the older nuclear data JENDL-3.2 and JEF-2.2 give rather good agreements with the experimental data. From the detailed study with an infinite unit cell model, it was found that the differences among the libraries are mainly due to the different fission cross section of U-235 in the energy rage below 1.0 eV.
U nuclear data to improve k
biases on U enrichment and temperature for low enriched uranium fueled lattices moderated by light waterWu, H.; Okumura, Keisuke; Shibata, Keiichi
JAERI-Research 2005-013, 31 Pages, 2005/06
JAERI-Research-2005-013.pdf:3.29MB
The under prediction of k depending on U enrichment in low enriched uranium fueled systems was studied in this report. Benchmark testing was carried out with several evaluated nuclear data files, including the new uranium evaluations from preliminary ENDF/B-VII and CENDL-3.1. Another problem reviewed here was k underestimation vs. temperature increase, which was observed in the slightly enriched system with recent JENDL and ENDF/B uranium evaluations. Through the substitute analysis of nuclear data of U and 
U, we propose a new evaluation of U data to solve both of the problems. The new evaluation was tested for various uranium fueled systems including low or highly enriched metal and solution benchmarks in the ICSBEP handbook. As a result, it was found that the combination of the new evaluation of U and the U data from the preliminary ENDF/B-VII gives quite good results for most of benchmark problems.
Okuno, Hiroshi; Takada, Tomoyuki
Journal of Nuclear Science and Technology, 41(4), p.481 - 492, 2004/04
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)Nuclear characteristic parameters were calculated and subcriticality judgement graphs were drawn for revision purposes of the Data Collection for the Nuclear Criticality Safety Handbook. The nuclear characteristic parameters were the neutron multiplication factor in infinite media, migration area and diffusion constants for 11 kinds of typical fuels encountered in criticality safety evaluation of nuclear fuel cycle facilities. These fuels included ADU-HO, UF6-HF and Pu(NO
)
-UO(NO) solution, of which data were not cited in the Data Collection. The calculation was made with the Japanese evaluated nuclear data library JENDL-3.2 and a sequence of criticality calculation codes, SRAC, POST and SIMCRI. The subcriticality judgement graphs that depict the region satisfying the inequality relation of the neutron multiplication factor less than 0.98 between the two variables (a) uranium enrichment, 239Pu/Pu ratio or plutonium enrichment and (b) H/(Pu+U) ratio were drawn for the same kinds of fuels except UF6-HF in infinite media.
Okuno, Hiroshi; Ryufuku, Susumu*; Suyama, Kenya; Nomura, Yasushi; Tonoike, Kotaro; Miyoshi, Yoshinori
JAERI-Conf 2003-019, p.116 - 121, 2003/10
This paper outlines the data prepared for the 2nd version of Data Collection of the Nuclear Criticality Safety Handbook. These data are discussed in the order of its preliminary table of contents. The nuclear characteristic parameters (k
, M
, D) were derived, and subcriticality judgment graphs were drawn for eleven kinds of fuels which were often encountered in criticality safety evaluation of fuel cycle facilities. For calculation of criticality data, benchmark calculations using the combination of the continuous energy Monte Carlo criticality code MVP and the Japanese Evaluated Nuclear Data Library JENDL-3.2 were made. The calculation errors were evaluated for this combination. The implementation of the experimental results obtained by using NUCEF facilities into the 2nd version of the Data Collection is under discussion. Therefore, related data were just mentioned. A database is being prepared to retrieve revised data easily.
Shibata, Keiichi; Kawano, Toshihiko*; Nakagawa, Tsuneo; Iwamoto, Osamu; Katakura, Junichi; Fukahori, Tokio; Chiba, Satoshi; Hasegawa, Akira; Murata, Toru*; Matsunobu, Hiroyuki*; et al.
Journal of Nuclear Science and Technology, 39(11), p.1125 - 1136, 2002/11
Times Cited Count：669 Percentile：96.97(Nuclear Science & Technology)Evaluation for JENDL-3.3 has been performed by considering the accumulated feedback information and various benchmark tests of the previous library JENDL-3.2. The major problems of the JENDL-3.2 data were solved by the new library: overestimation of criticality values for thermal fission reactors was improved by the modifications of fission cross sections and fission neutron spectra for U; incorrect energy distributions of secondary neutrons from important heavy nuclides were replaced with statistical model calculations; the inconsistency between elemental and isotopic evaluations was removed for medium-heavy nuclides. Moreover, covariance data were provided for 20 nuclides. The reliability of JENDL-3.3 was investigated by the benchmark analyses on reactor and shielding performances. The results of the analyses indicate that JENDL-3.3 predicts various reactor and shielding characteristics better than JENDL-3.2.
Okuno, Hiroshi; Nomura, Yasushi
Proceedings of the 2001 Topical Meeting on Practical Implementation of Nuclear Criticality Safety (CD-ROM), 8 Pages, 2001/11
The nuclear criticality safety handbook of Japan was first published in 1988, which was translated into English in 1995. This paper intends to introduce the American community of nuclear criticality safety to activities for revising the Japanese handbook, putting an emphasis on practical use of code validation. They include (1) publication of "Nuclear Criticality Safety Handbook, Version 2" and its English translation, (2) publication of "A Guide Introducing Burnup Credit, Preliminary Version," and (3) preparation of "Nuclear Criticality Safety Handbook, -Data Collection-, Version 2."
Working Group on Nuclear Criticality Satety Data
JAERI-Review 2001-028, 217 Pages, 2001/08
JAERI-Review-2001-028.pdf:10.04MB
no abstracts in English
Working Group on Nuclear Criticality Satety Data
JAERI 1340, 189 Pages, 1999/03
no abstracts in English
Komuro, Yuichi; Suzaki, Takenori; *; Sakurai, Kiyoshi; Horiki, Oichiro*
JAERI-Research 97-088, 19 Pages, 1997/11
JAERI-Research-97-088.pdf:0.86MB
no abstracts in English
Komuro, Yuichi; *
JAERI-Data/Code 96-002, 73 Pages, 1996/02
JAERI-Data-Code-96-002.pdf:2.65MB
no abstracts in English
Naito, Yoshitaka; Okuno, Hiroshi
JAERI-Review 95-013, 397 Pages, 1995/09
JAERI-Review-95-013.pdf:8.91MB
no abstracts in English
Kurosawa, Masayoshi; Naito, Yoshitaka; *
ICNC 95: 5th Int. Conf. on Nuclear Criticality Safety, Vol. I, 0, p.2.11 - 2.15, 1995/00
no abstracts in English
Tonoike, Kotaro; Izawa, Naoki; Okazaki, Shuji; Sugikawa, Susumu; Takeshita, Isao; *
ICNC 95: 5th Int. Conf. on Nuclear Criticality Safety,Vol. II, 0, p.10.25 - 10.32, 1995/00
no abstracts in English
July, 1993Research Committee on Reactor Physics
JAERI-M 93-254, 36 Pages, 1994/01
no abstracts in English
July 1992Research Committee on Reactor Physics
JAERI-M 92-209, 43 Pages, 1993/01
no abstracts in English
Nomura, Yasushi; Katakura, Junichi; Naito, Yoshitaka; Komuro, Yuichi; Okuno, Hiroshi
JAERI 1303, 152 Pages, 1986/11
no abstracts in English
Iwamoto, Hiroki; Nishihara, Kenji; Sugawara, Takanori; Tsujimoto, Kazufumi; Sasa, Toshinobu; Maekawa, Fujio
no journal, ,
