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Yokoyama, Kenji; Maruyama, Shuhei; Taninaka, Hiroshi; Oki, Shigeo
JAEA-Data/Code 2021-019, 115 Pages, 2022/03
JAEA-Data-Code-2021-019.pdf:6.21MB
JAEA-Data-Code-2021-019-appendix(CD-ROM).zip:435.94MB
In JAEA, several versions of unified cross-section set for fast reactors have been developed so far; we have developed a new unified cross-section set ADJ2017R, which is an improved version of the unified cross-section setADJ2017 for fast reactors. The unified cross-section set is used for reflecting information of C/E values (analysis / experiment values) obtained by integral experiment analyses in reactor core design via the cross-section adjustment methodology; the values are stored in the standard database for FBR core design. In the methodology, the cross-section set is adjusted by integrating the information such as uncertainty (covariance) of nuclear data, uncertainty of integral experiment / analysis, sensitivity of integral experiment with respect to nuclear data. ADJ2017R basically has the same performance as ADJ2017, but we conducted an additional investigation on ADJ2017 and revised the following two points. The first is to unify the evaluation method of the correlation coefficient of uncertainty caused by experiments (hereinafter referred to as the experimental correlation coefficient). Because it was found that the common uncertainty used in the evaluation of the experimental correlation coefficient was evaluated by two different methods, the experimental correlation coefficients were revised for all experimental data, and the evaluation method was unified. The second is the review of the integral experiment data used for the cross-section adjustment calculation. It was found that one of the experimental values of composition ratio after irradiation of the Am-243 sample has a problem in uncertainty evaluation because its experimental uncertainty is extremely small compared to the others. The cross-section adjustment calculation was, therefore, redone by excluding the experimental value. In the creation of ADJ2017, a total of 719 data sets were analyzed and evaluated, and eventually adopted 620 integral experimental data sets. In contrast, a total of 61
Yokoyama, Kenji; Ishikawa, Makoto*
Annals of Nuclear Energy, 154, p.108100_1 - 108100_11, 2021/05
Times Cited Count：1 Percentile：16.35(Nuclear Science & Technology)In the design of innovative nuclear reactors such as fast reactors, the improvement of the prediction accuracies for neutronics properties is an important task. The nuclear data adjustment is a promising methodology for this issue. The idea of the nuclear data adjustment was first proposed in 1964. Toward its practical application, however, a great deal of study has been conducted over a long time. While it took about 10 years to establish the theoretical formulation, the research and development for its practical application has been conducted for more than half a century. Researches in this field are still active, and the fact suggests that the improvement of the prediction accuracies is indispensable for the development of new types of nuclear reactors. Massimo Salvatores, who passed away in March 2020, was one of the first proposers to develop the nuclear data adjustment technique, as well as one of the great contributors to its practical application. Reviewing his long-time works in this area is almost the same as reviewing the history of the nuclear data adjustment methodology. The authors intend that this review would suggest what should be done in the future toward the next development in this area. The present review consists of two parts: a) the establishment of the nuclear data adjustment methodology and b) the achievements related to practical applications. Furthermore, the former is divided into two aspects: the study on the nuclear data adjustment theory and the numerical solution for sensitivity coefficient that is requisite for the nuclear data adjustment. The latter is separated to three categories: the use of integral experimental data, the uncertainty quantification and design target accuracy evaluation, and the promotion of nuclear data covariance development.
Kurihara, Momo*; Yasutaka, Tetsuo*; Aono, Tatsuo*; Ashikawa, Nobuo*; Ebina, Hiroyuki*; Iijima, Takeshi*; Ishimaru, Kei*; Kanai, Ramon*; Karube, Jinichi*; Konnai, Yae*; et al.
Journal of Radioanalytical and Nuclear Chemistry, 322(2), p.477 - 485, 2019/11
Times Cited Count：2 Percentile：21.58(Chemistry, Analytical)We assessed the repeatability and reproducibility of methods for determining low dissolved radiocesium concentrations in freshwater in Fukushima. Twenty-one laboratories pre-concentrated three of 10 L samples by five different pre-concentration methods (prussian-blue-impregnated filter cartridges, coprecipitation with ammonium phosphomolybdate, evaporation, solid-phase extraction disks, and ion-exchange resin columns), and activity of radiocesium was measured. The z-scores for all of the 
Cs results were within 
2, indicating that the methods were accurate. The relative standard deviations (RSDs) indicating the variability in the results from different laboratories were larger than the RSDs indicating the variability in the results from each separate laboratory.
Yokoyama, Kenji; Kitada, Takanori*
Proceedings of 2018 International Congress on Advances in Nuclear Power Plants (ICAPP 2018) (CD-ROM), p.1221 - 1230, 2018/04
no abstracts in English
Nakajima, Kunihisa
Mass Spectrometry (Internet), 5(2), p.S0055_1 - S0055_6, 2016/12
Though equilibrium vapor pressures are utilized to determine thermodynamic properties of not only gaseous species but also condensed phases, the obtained data often disagree by a factor of 100 and more. A new data analysis method is proposed using the so-called second and third law procedures to improve accuracy of vapor pressure measurements. It was found from examination of vapor pressures of cesium metaborate and silver that the analysis of the difference between the second and third law values can result in determination of an optimal data set. Since the new thermodynamic method does not require special techniques and or experiences in dealing with measured data, it is reliable and versatile to improve the accuracy of vapor pressure evaluation.
Yokoyama, Kenji; Maruyama, Shuhei; Numata, Kazuyuki; Ishikawa, Makoto; Takeda, Toshikazu*
Proceedings of International Conference on the Physics of Reactors; Unifying Theory and Experiments in the 21st Century (PHYSOR 2016) (USB Flash Drive), p.1906 - 1915, 2016/05
Kitada, Takanori*; Okumura, Keisuke; Unesaki, Hironobu*; Saji, Etsuro*
Proceedings of International Conference on Physics of Fuel Cycles and Advanced Nuclear Systems; Global Developments (PHYSOR 2004) (CD-ROM), 8 Pages, 2004/04
Burnup calculation benchmark has been carried out for the LWR next generation fuels aiming at high burnup up to 70 GWd/t with UO
and MOX. Based on the submitted results by many benchmark participants, the present status of calculation accuracy has been confirmed for reactor physics parameters of the LWR next generation fuels, and the factors causing the calculation differences were analyzed in detail. Moreover, the future experiments and research subjects necessary to reduce the calculation differences were discussed and proposed.
Research Committee on Reactor Physics
JAERI-Research 2004-004, 409 Pages, 2004/03
JAERI-Research-2004-004.pdf:28.53MB
This report summarizes the second phase (FY2001-2002) activity of "the Working Party (WP) on Reactor Physics for LWR Next Generation Fuels". The next generation fuels mean the ones aiming at further extended burn-up such as 70GWd/t over the current design. In the WP, the benchmark activity has been conducted to investigate and improve the calculation accuracy of the nuclear characteristics of the next generation fuels. In the second phase activity, all benchmark results were compiled and compared. Based on the comparison, the present status of calculation accuracy for the next generation fuels has been confirmed, and the factors causing the calculation differences were analyzed in detail. Moreover, analyses of the post irradiation and critical experiments with the codes used in the benchmark were reviewed, and future experiments and research subjects necessary to reduce the calculation differences were discussed and proposed.
Okumura, Susumu; Arakawa, Kazuo; Fukuda, Mitsuhiro; Nakamura, Yoshiteru; Yokota, Wataru; Ishimoto, Takayuki; Kurashima, Satoshi; Ishibori, Ikuo; Nara, Takayuki; Agematsu, Takashi; et al.
Nukleonika, 48(Suppl.2), p.S35 - S37, 2003/00
In the JAERI AVF cyclotron, unstable phenomena, such as beam intensity decrease, were observed. We found that an increase in temperature of the iron body of the magnet induced the drift of the magnetic field. Stabilization of the iron body temperature was achieved. We have developed a nuclear magnetic resonance (NMR) magnetometer with an accuracy of the order of 10
to measure the stability of the cyclotron magnetic field with a large gradient by using a pair of correction coils to reduce the field gradient and by eliminating the effect of the RF.
Tamada, Masao; Kasai, Noboru; Seko, Noriaki; Hasegawa, Shin; Kawabata, Yukiya*; Onuma, Kenji*; Takeda, Hayato*; Katakai, Akio; Sugo, Takanobu
JAERI-Tech 2001-065, 39 Pages, 2001/11
JAERI-Tech-2001-065.pdf:5.24MB
Positioning and monitoring system for marine component in recovery equipment of significant metals from seawater by using adsorbent was designed and assembled to avoid unexpected accidents. This system which was set on float part of the marine component obtains the position data by means of GPS satellites and send them to Takasaki and Mutsu establishments through satellite communication. As characteristic test for 20 days in the real sea, 256 data were obtained every 2 hours. The wrong data was eight and the positioning accuracy was 200.7m. To improve these characteristics, two new functions were added to the present firmware. These are to raise positioning resolutions in longitude and latitude from 0.001 to 0.00001 degree and to average remaining three data of positioning after maximum and minimum data were removed from continuous five times positioning. The improved system shows no wrong datum, average positioning of 6.74m. This performance is enough to prevent marine equipment from its drifting accident.
Research Committee on Reactor Physics
JAERI-Research 2001-046, 326 Pages, 2001/10
JAERI-Research-2001-046.pdf:14.45MB
The Working Party on Reactor Physics for LWR Next Generation Fuels in the Research Committee on Reactor Physics, which is organized by the Japan Atomic Energy Research Institute, has recently proposed a series of benchmark problems to investigate the calculation accuracy of the nuclear characteristics of LWR next generation fuels. The next generation fuels mean the ones aiming for further extended burnup such as 70GWd/t over the current design. The resultant specifications of the benchmark problem therefore neglect some of the current limitations such as 5wt%235U to achieve the above-mentioned target. The Working Party proposed six benchmark problems, which consist of pin-cell, PWR assembly and BWR assembly geometries loaded with uranium and MOX fuels, respectively. The present report describes the detailed specifications of the benchmark problems. The results of preliminary analyses performed by the eleven member organizations and their comparisons are also presented.
Oigawa, Hiroyuki; Iijima, Susumu
JAERI-Research 95-007, 93 Pages, 1995/02
JAERI-Research-95-007.pdf:2.7MB
no abstracts in English
Yamano, Naoki*; Tabara, Takashi*; ; Masukawa, Fumihiro; Naito, Yoshitaka
JAERI-M 90-183, 142 Pages, 1990/10
no abstracts in English
Mori, Seiji*; *; Seki, Yasushi
JAERI-M 88-103, 40 Pages, 1988/06
no abstracts in English
Nuclear Science and Engineering, 97, p.145 - 160, 1987/00
Times Cited Count：2 Percentile：29.78(Nuclear Science & Technology)no abstracts in English
; ; ; ;
Theory and Practices in Radiation Protection and Shielding, p.570 - 577, 1987/00
no abstracts in English
; ; ; *
Journal of Nuclear Science and Technology, 22(5), p.358 - 370, 1985/05
Times Cited Count：13 Percentile：81.94(Nuclear Science & Technology)no abstracts in English
Akabori, Mitsuo; Shiba, Koreyuki
JAERI-M 84-167, 15 Pages, 1984/09
no abstracts in English
JAERI-M 84-040, 90 Pages, 1984/03
no abstracts in English
; ; Shiba, Koreyuki
J.Phys.,E, 17, p.339 - 341, 1984/00
no abstracts in English
