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Chiba, Go*; Yamamoto, Akio*; Tada, Kenichi
Journal of Nuclear Science and Technology, 60(2), p.132 - 139, 2023/02
Times Cited Count：2 Percentile：50.96(Nuclear Science & Technology)A new multi-group neutronics analysis sequence ACE-FRENDY-CBZ is proposed. This sequence is free from uses of any application libraries; with the ACE files as the starting point, multi-group cross section data of media comprising a target system are calculated with the FRENDY code, and multi-group neutron transport calculations are performed with modules of the CBZ code system. The ACE-FRENDY-CBZ sequence was tested against the eight fast neutron systems, and good agreement with the reference Monte Carlo results was obtained within 30 pcm differences in the bare systems and the thorium-reflected system, and approximately 100 pcm differences in the uranium-reflected systems. The use of the current-weighted total cross sections in the multi-group neutron transport calculations had non-negligible impacts over 100 pcm on k-eff, and the calculations with the current-weighted total cross sections systematically underestimated k-eff in the uranium-reflected systems.
Endo, Akira; Kim, E.; Yamaguchi, Yasuhiro
JAERI-Data/Code 2001-027, 62 Pages, 2001/10
JAERI-Data-Code-2001-027.pdf:2.05MB
SCINFUL has been used to calculate response functions of organic scintillators for high-energy neutron spectroscopy. However, the applicability of SCINFUL is limited to the calculations for cylindrical NE213 and NE110 scintillators. In the present study, SCINFUL-CG was developed by introducing a geometry specifying function and high-energy neutron cross-section data into SCINFUL. The geometry package MARS-CG, the extended version of the CG (Combinatorial Geometry), was programmed into SCINFUL-CG to express various geometries of detectors. Neutron spectra in the regions specified by the CG can be evaluated by the track length estimator. The cross section data of silicon, oxygen and aluminum for neutron transport calculation were incorporated up to 100MeV using the data of LA150. Validity of SCINFUL-CG was examined by comparing calculated results with those by SCINFUL and MCNP and experimental data. SCINFUL-CG can be used for the designs of high-energy neutron spectrometers and neutron monitors using the organic scintillators. The present report is a user's manual of SCINFUL-CG.
Yamamoto, Toshihiro; Miyoshi, Yoshinori
Journal of Nuclear Science and Technology, 36(11), p.1069 - 1075, 1999/11
Times Cited Count：2 Percentile：21.18(Nuclear Science & Technology)no abstracts in English
Hunter
JNC TN9400 99-049, 74 Pages, 1999/04
This document describes a series of calculations that were carried out to model various measurements from the BFS-58-1-I1 experiment. BFS-58-1-I1 was a mock-up of a uranium-free, Pu burning core at BFS-2, a Russian critical assembly operated by IPPE. The experiment measured values of keff, Na void reactivity worth, material sample reactivity worths and reaction rate ratios. The experiments were modelled using a number of different methods. Basic nuclear data was taken from JENDL-3.2, in either 70 or 18 groups. Cross-section data for the various material regions of the assembly were calculated by either SLAROM or CASUP; the heterogeneous structure of the core regions was modelled in these calculations, with 3 different options considered for representing the (essentially 2d) geometry of the assembly components in a 1D cell model. Whole reactor calculations of flux and keff were done using both a diffusion model (CITATION) and a transport model (TWOTRAN2), both using an RZ geometry. Reactivity worths were calculated both directly from differences in keff values and by using the exact perturbation calculations of PERKY and SN-PERT (for CITATION and TWOTRAN2, respectively). Initial calculations included a number of inaccuracies in the assembly representation, a result of communication difficulties between JNC and IPPE; these errors were removed for the final calculations that are presented. Calculations for the experiments have also been carried out in Russia (IPPE) and France (CEA) as part of an international comparison exercise, some of those results are also presented here. The calculated value of keff was 1.1%
k/k higher than the measured value, Na void worth C/E values were 
1.06; these results were considered to be reasonable. (Discrepancies in certain Na void values were probably due to experimental causes, though the efect should be investigated in any future experiments.) several sample worth values were small compared with calculational uncertaint
Sasa, Toshinobu; Tsujimoto, Kazufumi; Takizuka, Takakazu; Takano, Hideki
JAERI-Data/Code 99-007, 65 Pages, 1999/03
JAERI-Data-Code-99-007.pdf:2.12MB
no abstracts in English
Mizuno, Masahiro*; Uto, Nariaki
JNC TN9400 98-007, 147 Pages, 1998/11
A design study of a new in-pile experimental reactor, SERAPH (Safety Engineering Reactor for Accident PHenomenology), for FBR safety research has progressed at JNC (Japan Nuclear Cycle Development Institute). SERAPH is intended for various in-pile experiments to be performed under steady state and various transient operation modes. Heavy water is selected as a coolant material for heat removal of the SERAPH driver core during the experiments. Control rods are needed to conduct the experiments, and a control rod with heavy water follower is considered as one of the promising ideas and is now under investigation. In this idea, care must be taken to avoid production of local power peaks which are caused by neutron moderation in the follower and may appear in the vicinity of the boundary between the control rod and its neighboring fuel subassembly, since deuterium has an excellently high moderation power. Therefore, preparation of some methods of evaluating power density distribution in detail is required for control rod design. This report describes preparation of a set of neutronic calculation methods to evaluate intra-subassembly power density distribution including local power peaks around a control rod. A two-dimensional S
transport calculation code TWOTRAN-II is selected as a tool for evaluating neutron transport phenomena near the control rod with no cares for statistical influence. A two-dimensional rectangular super-cell model, which is a physical model composed of a control rod and its surrounding fifteen fuel sub-assemblies, and a method to construct the super-cell model based on thirteen unit cells are created, considering neutron mean free path near a control rod. Two processing tools are newly developed to generate a material region map and mesh boundaries for an efficient super-cell construction procedure and to obtain pin-wise power densities based on calculated mesh-wise neutron flux data. The results in this report are expected to be ...
Takeda, Toshikazu*; Kitada, Takanori*; *; *
PNC TJ9605 98-001, 267 Pages, 1998/03
As the improvement of numerical analysis method for FBR core characteristics, studies on several topics have been conducted; multiband method, Monte Carlo perturbation and nodal transport method. This report is composed of the following three parts. Part 1: Improvement of Reaction Rate Calculation Method in the Blanket Region Based on the Multiband Method. A method was developed for precise evaluation of the reaction rate distribution in the blanket region using the multiband method. With the 3-band parameters obtained from the ordinary fitting method, major reaction rates such as U-238 capture, U-235 fission, Pu-239 fission and U-238 fission rate distributions were analyzed. As for the nuclides to be analyzed, the elements of structure material, such as iron, nickel, chrome and sodium were considered. By the present method, all the reactions became larger at the deep region in the blanket. The maximum correction amounted as much as 5%. This tendency lessen the disagreement between the ordinary calculation and the experiment. It was made clear that the treatment in inter-band scattering term is veryimportant because it has large sensitivity on the result. An alternative method to determine the multiband parameters whieh method is based on more direct approach and is free from drawbacks in the present method, was also investigated. Part 2 : Improvement of Estimation Method for Reactivity Based on Monte-Carlo Perturbation Theory. Perturbation theory based on Monte-Carlo perturbation theory have been investigated and introduced into the calculational code. The continuous energy Monte-Carlo perturbation code has been developed by using not only the correlated sampling method which is already used before, but also the derivative operator sampling method. The Monte-Carlo perturbation code was applied to MONJU core and the calculational results were compared to the reference. The change of eigenvalue caused by the change of sodium density in the GEM or dummy ...
Fletcher, J. K.
PNC TN9410 97-065, 25 Pages, 1997/07
None
Takeda, Toshikazu*; *; Kitada, Takanori*; *
PNC TJ9605 97-001, 100 Pages, 1997/03
This report is composed of the following two parts and appendix. (I)Improvement of the Method for Evaluating Reactivity Based on Monte Carlo Perturbation Theory (II)Improvement of Nodal Transport Method for 3-D Hexagonal Geometry (Appendix) Effective Cross Section of 
U Samples for Analyzing Doppler Reactivity in Fast Reactors Part I. Improvement of the Method for Evaluating Reactivity Bascd on Monte Carlo Perturbation Theory. Theoretical formulation in Monte Carlo perturbation method had been checked, and then introduced into a calculation code. The increase of CPU time is about 10 to 20 % compared to that if normal Monte Carlo code, in the cases of same number of history. This Monte Carlo perturbation method found to be effective, because results are almost reasonable and deviations of the results are especially small, by using the Monte Carlo perturbation code. However, there are somc cases that the results of the change of eigenvalues becomes positive or negative by changing the estimator, and there is no reasonable difference in the results between the conventional method, which does not consider the change of neutron source distribution caused by a perturbation, and the new method, which consider that change. Thus it is still necessary to check the Monte Carlo pcrturbation code. Part II. Improvement of Nodal Transport Method for 3-D Hexagonal Geometry It is certain that we can accurately evaluate hexagonal geometry FBR core by nodal transport calculation code for hexagonal-Z geometry named 'NSHEX'. However it is also found that in very heterogeneous core the results is not good enough. Because the treatment of the transverse leakage to the radial direction, which is use for evaluating intra-nodal flux distribution, is not so accurate. For the treatment of the leakage distribution, it is necessary to estimate the nodal vertex flux. In conventional method, the vertex flux estimated by the surrounding node surfacc flux around that vertex. On the contrary,
*
PNC TN9410 92-278, 347 Pages, 1992/09
A series of critical experiments for conventional two-zone homogeneous cores of 6 to 8 MWe-class LMFBR, JUPITER phase-I, were analyzed and evaluated using the latest analytical method, which had been established from the preceding numerous studies on fast reactor physics. The present work is a part of efforts to develop a standard data base for LMFBR core nuclear design at PNC. The analytical method and results are summarized as follows: (1)Analytical method (a)Nuclear data : 70-group fast reactor constant set JFS-3-J2(1989 edition) based on the Japanese Evaluated Nudear Data Library, version 2 (JENDL-2). (b)Cell calculation : plate stretch model, cell heterogeneity treatment by Tone's method and transport cross-sections weighted with neutron current. (c)Base core calculation : 18-group, three-dimensiona1 XYZ diffusion theory and Benoist's anisotropic diffusion coefficients. (d)Correction calculation : three-dimensional transport effect, mesh size effect, cell asymmetric effect and all master model effect etc. (2)Analytical results (a)The C.E (calculation/experiment) values of criticality agree quite well among seven cores (ZPPR-910D/2) and do not depend on the core volume or the number of control rod positions (CRP). (b)The C/E values of control rod worths increase gradually from the core center to the core edge positions in each core (511%). Those of reaction rate distributions also indicate similar spatial variations (25%), which is considered to be consistent with the C/E tendency of control rod worths. (c)The reaction rate ratios of C28/F49 and F25/49 give quite stable C/E values of 1.06 and 1.03, respectively. (d)The C/E values of sodium void reactivities are overestimated by +25% at core center region. The C/E dependence on void region size, which was pointed out in the past analyses, is found in the ZPPR-9 core, but not in the ZPPR-10 series. (e)The C/E dependence of 4% on the radial positions were found in sample ...
Chatani, Keiji; ; ; ; *; *; *
PNC TN9410 92-076, 348 Pages, 1992/03
JASPER (Japanese American Shielding Program of Experimental Researches) is the cooperative research program between PNC and US-DOE using TSF (Tower Shielding Facility) in ORNL (Oak Ridge National Laboratory) as the experiment facility. This report summarizes the works in FY'1991 as follows; Planning the experiment configuration for JASPER Program, Analyses of the JASPER Program experiment, Analyses of the former TSF experiment, and Development of the methods for FBR shielding analyses. (1)Analyses of the JASPER Program Experiment In FY'1991 Axial shield Experiment data were mainly analyzed, and some of In-vessel Fuel Storage (IVS) Experiment data were also analyzed. The Fast Reactor Shielding Analysis System developed by PNC has been applied to the analyses for JASPER Program experiments. (Axial Shield Experiment Analysis) Axial Shield Experiment was conducted from August 1990 through December 1990 as part of a continuing series of eight experimennts planned for the JASPER Program. The experiment serves not only to provide data for the verification of analysis system in calculating the neutron streaming in each design, but also to provide a basis for determining the shielding effectiveness of stainless steel (SS) and boron carbide (B
C). four types of experimental configuration were used. The conclusions of the analyses are as follows: (a)For the spectrum modifier which provides a spectrum of neutron representative of those incident on the axial shield for the FBR core, the two-dimensional calculation showed good agreement with the experimental data. It was confirmed that the two-dimensional calculation could estimate the experimental data with almost the same accuracy as in the analyses for the Radial shield Attenuation and the Fission Gas Plenum Experiments. (b)For the homogeneous mockups, the two-dimensional ealculation could give the good agreement with the experimental data. (c)For the central blockage type mockups, in which the coolant flows ...
Takeda, Toshikazu*; Ito, Noboru*; Kugo, Teruhiko*; Takamoto, Masanori*; Aoki, Shigeaki*; Kawagoe, Yoshihiro*; Sengoku, Katsuhisa*; Tanaka, Motonari*; Yoshimura, Akira*; Tamitani, Masashi*; et al.
PNC TJ2605 89-001, 251 Pages, 1989/03
no abstracts in English
Suzaki, Takenori; Yanagisawa, Hiroshi; Kobayashi, Iwao
Proc. of the Int. Topical Meeting on Safety Margins in Criticality Safety, p.112 - 119, 1989/00
no abstracts in English
; ; *;
JAERI-M 82-086, 38 Pages, 1982/07
no abstracts in English
PNC TJ250 82-13, 44 Pages, 1982/03
None
; *; *;
JAERI-M 6935, 55 Pages, 1977/03
no abstracts in English
Journal of the Physical Society of Japan, 41(6), p.2020 - 2026, 1976/06
Times Cited Count：0no abstracts in English
; ; ; *
JAERI-M 5793, 48 Pages, 1974/07
no abstracts in English
