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Ueki, Taro
Proceedings of 12th International Conference on Nuclear Criticality Safety (ICNC2023) (Internet), 9 Pages, 2023/10
A Monte Carlo Solver Solomon has been under development as an object-oriented code written in the C++14 standards. It consists of regular capabilities of criticality safety analysis and a special capability of random media criticality. In the latter capability, Solomon is equipped with a class for the random media modeled by the incomplete randomized Weierstrass function (IRWF). By this modeling, the uncertainty of random media criticality can be evaluated by executing criticality calculations over many IRWF-replicas. However, it is impossible to know beforehand how many IRWF-replicas should be computed. To deal with this issue, a bounded amplification (BA) technique has been newly equipped in Solomon. Applying BA to IRWF, it is possible to reduce the number of IRWF-replicas by more than 95% in terms of the upper limit estimation of neutron effective multiplication factor. Solomon is also equipped with a voxel-overlay (VO). This functionality is shown to be valuable for evaluating the resonance self-shielding effect.
Ueki, Taro
Progress in Nuclear Energy, 144, p.104099_1 - 104099_7, 2022/02
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)Randomized Weierstrass function (RWF) has been under development for evaluating the uncertainty of random media criticality due to the material mixture under disorder. In this work, the modelling capability of RWF is refined so that the spectrum range can be controlled by specifying its lower and upper ends of the frequency domain variable. As a result, it becomes possible to make fair criticality comparison among replicas of random media under inverse power law power spectra. Technically, the infinite sum of trigonometric terms in RWF is extended to cover the arbitrarily low frequency domain and then truncated to finite terms for the sole purpose of spectrum range control. This means that the refinement is free of the convergence issue towards a fractal characteristic of Weierstrass function and thus termed Incomplete Randomized Weierstrass function (IRWF). As a demonstration, a three-dimensional version of IRWF is applied to the mixture of three fuels with different burnups in a water-moderated environment. Monte Carlo criticality calculations are carried out to evaluate the uncertainty of neutron effective multiplication factor due to the indeterminacy of the fuel mixture formation.
Tada, Kenichi
Proceedings of 27th International Conference on Nuclear Engineering (ICONE-27) (Internet), 4 Pages, 2019/05
The decommissioning of Fukushima Daiichi Nuclear Power Plant accident is one of the most important issues in Japan. The criticality safety of fuel debris is imperative to prevent exposure of workers. The investigating criticality monitoring system cannot detect the criticality of fuel debris quickly. The estimation of criticality of fuel debris is required for the fuel debris retrieval. Though the expert knowledge of reactor physics is necessary to estimate the criticality of fuel debris, many people who make a plan of fuel debris retrieval may not know well about criticality analysis. We developed a handy criticality analysis tool HAND to quickly estimate the criticality of fuel debris without expert knowledge of reactor physics. Since the input data of HAND is so simple and users can intuitively understand the calculation results, this tool is expected to be the effective tool to estimate the criticality of fuel debris.
; Numata, Kazuyuki*; ; *; Oigawa, Hiroyuki*
JNC TY9400 2000-006, 162 Pages, 2000/04
JNC-TY9400-2000-006.pdf:4.57MB
no abstracts in English
Yokoyama, Kenji*; Numata, Kazuyuki*; Ishikawa, Makoto*; Oigawa, Hiroyuki; Iijima, Susumu
JNC-TY9400 2000-006, 168 Pages, 2000/04
no abstracts in English
; Numata, Kazuyuki*
JNC TN9400 2000-036, 138 Pages, 2000/03
JNC-TN9400-2000-036.pdf:10.16MB
Japan Nuclear Cycle Development lnstitute (JNC) had developed the adjusted nuclear cross-section library in which the results of the JUPITER experiments were renected. Using this adjusted library, the distinct improvement of the accuracy in nuclear design of FBR cores had been achieved. As a recent research, JNC develops a database of other integral data in addition to the JUPITER experiments, aiming at further improvement for accuracy and reliability. ln this report, the authors describe the evaluation of the C/E values and the sensitivity analysis for the Experimental Fast Reactor "JOYO" MK-l core. The minimal criticality, sodium void reactivity worth, fuel assembly worth and burn-up coefficient were analyzed. The results of both the minimal criticality and the fuel assembly worth, which were calculated by the standard analytical method for JUPITER experiments, agreed well with the measured values. 0n the other hand, the results of the sodium void reactivity worth have a tendency to overestimate. As for the burn-up coefficient, it was seen that the C/E values had a dispersion among the operation cycles. The authors judged that further investigation for the estimation of the experimental error will increase the applicability of the integral data to the adjusted library. Furthermore, sensitivity analyses for the minimal criticality, sodium void reactivity worth and fuel assembly worth showed the characteristics of "JOYO" MK-l core in comparison with ZPPR-9 core of JUPITER experiments.
Ando, Masaki; Iijima, Susumu; Ishikawa, Makoto*; Iwai, Takehiko*
JAERI-Tech 2000-025, p.45 - 0, 2000/03
JAERI-Tech-2000-025.pdf:1.77MB
no abstracts in English
Ando, Masaki; Iijima, Susumu; Okajima, Shigeaki; Sakurai, Takeshi; Oigawa, Hiroyuki
JAERI-Research 2000-017, p.36 - 0, 2000/03
JAERI-Research-2000-017.pdf:1.48MB
no abstracts in English
Oigawa, Hiroyuki; Iijima, Susumu; Sakurai, Takeshi; Okajima, Shigeaki; Ando, Masaki; Nemoto, Tatsuo; Kato, Yuichi*; Osugi, Toshitaka
Journal of Nuclear Science and Technology, 37(2), p.186 - 201, 2000/02
no abstracts in English
Osugi, Toshitaka
Dai-30-Kai Robutsuri Kaki Semina Tekisuto, p.118 - 137, 1998/00
no abstracts in English
*
PNC TN9410 93-010, 502 Pages, 1992/12
The present report compiles the experimental data of JUPITER phase-I, which was a joint research program between U.S.DOE and PNC of Japan, using the ZPPR facility at ANL-Idaho in 1978 to 1979. The JUPITER-I experiment was a series of critical experiments for conventional two-zone homogeneous cores of 600 to 800 MWe-class LMFBR, including seven experimental cores The nuclear characteristics recorded here include criticality, control rod reactivity, reaction rate distribution, sodium void reactivity, sample reactivity, Doppler reactivity, gamma heating and neutron spectrum. (1)ZPPR-9 : two-region cylindrical clean core with volume of app. 4,600 liters, (2)ZPPR-10A : hexagonal engineering-mockup core with 19 cotrol-rod positions(CRPs), (3)ZPPR-10B : changes seven CRPs to control rods(CRs) from ZPPR-10A, (4)ZPPR-10C : volume of app. 6,200 liters with similar core arrangement to ZPPR-10A, (5)ZPPR-10D : 31 CRPs with the same volume as ZPPR-10C, (6)ZPPR-10D/1 : changes the central CRP to a CR from ZPPR-10D, and, (7)ZPPR-10D/2 : changes seven CRPs to CRs from ZPPR-10D. The present work is a part of efforts to develop a standard data base for LMFBR core nuclear design at PNC. The detail of experimental data is thoroughly recorded here so as to re-analyze these experiments in future. In addition, these experimental data are installed in the computer system at OEC for convenience of analytical code input.
; Miyoshi, Yoshinori; Tachimori, Shoichi
JAERI-M 91-184, 31 Pages, 1991/11
no abstracts in English
;
JAERI-M 83-188, 61 Pages, 1983/11
no abstracts in English
; ; Nakagawa, Masayuki
Nihon Genshiryoku Gakkai-Shi, 19(8), p.508 - 519, 1977/08
Times Cited Count：0no abstracts in English
Iijima, Tsutomu
JAERI-M 6063, 19 Pages, 1975/03
no abstracts in English
Iijima, Tsutomu; ; ; ; ; ;
JAERI-M 6062, 9 Pages, 1975/03
no abstracts in English
Iijima, Tsutomu; ; ; *; ;
JAERI-M 5890, 28 Pages, 1974/11
no abstracts in English
Sakai, Hironori
no journal, ,
Quantum criticalities tuned by pressure, external field, and chemical substitutions mark an important link in the heavy fermion superconductors. Systematic NMR investigations have suggested that 
-type antiferromagnetic spin fluctuations are favorable for 
-wave superconductivity in 115 compounds. Recently, anisotropy of antiferromagnetic spin fluctuations is now being microscopically examined in several other tetragonal systems like CeRh
Si under pressures. Moreover, electrical inhomogeneity near quantum critical point is also detected in the chemically substituted CeCoIn
.
; Around Kondo holesSakai, Hironori; Hattori, Taisuke; Tokunaga, Yo; Kambe, Shinsaku; Yokoyama, Makoto*; Zhu, J.-X.*; Ronning, F.*; Bauer, E. D.*; Thompson, J. D.*
no journal, ,
We have used nuclear quadrupole resonance (NQR) to probe microscopically the response of a prototypical quantum critical metal CeCoIn to substitutions of small amounts of Cd or Zn for In. Such non-magnetic Cd or Zn substitutions induce a long range antiferromagnetism. In the case of the Cd substitutions, approximately half of the Cd substituents induce local Ce moments in their close proximity, as observed by site-dependent longitudinal nuclear spin relaxation rates 
. In the case of Zn substitutions, the similar site dependence of is observed as well. We will discuss about the heterogeneous electronic state realized in such a dilutely substituted system.
