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Tanimura, Yoshihiko; Yoshitomi, Hiroshi
Nihon Genshiryoku Gakkai-Shi ATOMO
, 66(1), p.42 - 45, 2024/01
no abstracts in English
Akiyama, Yoichi; Shibanuma, So; Yanagisawa, Kenichi*; Yamada, Taichi; Suzuki, Kenta; Yoshida, Moeka; Ono, Takahiro; Kawabata, Kuniaki; Watanabe, Kaho; Morimoto, Kyoichi; et al.
JAEA-Review 2023-015, 60 Pages, 2023/09
JAEA-Review-2023-015.pdf:4.78MB
Naraha Center for Remote Control Technology Development (NARREC) was established in Japan Atomic Energy Agency to promote a decommissioning work of Fukushima Daiichi Nuclear Power Station (Fukushima Daiichi NPS). NARREC consists of a Full-scale Mock-up Test Building and Research Management Building. Various test facilities are installed in these buildings for the decommissioning work of Fukushima Daiichi NPS. These test facilities are intended to be used for various users, such as companies engaged in the decommissioning work, research and development institutions, educational institutions and so on. The number of NARREC facility uses was 84 in FY2021. We participated booth exhibitions and presentations on the decommissioning related events. Moreover, we also contributed to the development of human resources by supporting the 6th Creative Robot Contest for Decommissioning. As a new project, "Narahakko Children's Classroom" was implemented for elementary school students in Naraha Town. This report summarizes the activities of NARREC in FY2021, such as the utilization of facilities and equipment of NARREC, the development of remote-control technologies for supporting the decommissioning work, arrangement of the remote-control machines for emergency response, and training for operators by using the machines.
Yoshitomi, Hiroshi
Isotope News, (786), p.26 - 29, 2023/04
no abstracts in English
Ueki, Taro
Nuclear Science and Engineering, 194(6), p.422 - 432, 2020/06
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)In Monte Carlo criticality calculation, the convergence-in-distribution check of the sample mean of tallies can be approached in terms of the influence range of autocorrelation. In this context, it is necessary to evaluate the attenuation of autocorrelation coefficients over lags. However, in just one replica of calculation, it is difficult to accurately estimate small ACCs at large lags because of the comparability with statistical uncertainty. This paper proposes a method to overcome such an issue. Its essential component is the transformation of a standardized time series of tallies so that the resulting series asymptotically converges in distribution to Brownian motion. The convergence-in-distribution check is constructed based on the independent increment property of Brownian motion. The judgment criterion is set by way of the spectral analysis of fractional Brownian motion. Numerical results are demonstrated for extreme and standard types of criticality calculation.
Kawabata, Kuniaki
Japanese Journal of Applied Physics, 59(5), p.050501_1 - 050501_9, 2020/05
Times Cited Count：11 Percentile：18.54(Physics, Applied)This paper describes the decommissioning work being undertaken at the Fukushima Daiichi Nuclear Power Station of the Tokyo Electric Power Company Holdings Inc.'s (FDNPS) using remote controlled robotic systems, as well as lessons learned from past remote task executions. We also summarize the issues to be considered in promoting safe, steady, and efficient decommissioning based on past experiences. In response to these issues, we are developing test methods for performance evaluation of the robots for nuclear decommissioning, robot simulator for operator proficiency training, and information generation methods to improve the operator's status awareness. The current status of technological development is also described.
Kawabata, Kuniaki
Nihon Robotto Gakkai-Shi, 36(7), p.460 - 463, 2018/09
no abstracts in English
Okazaki, Hiro; Shibano, Koya; Abe, Katsuo; Sumi, Mika; Kayano, Masashi; Kageyama, Tomio; Mason, P.*
Proceedings of INMM 57th Annual Meeting (Internet), 7 Pages, 2016/07
The reference materials used for accountancy analysis by IDMS, referred to as LSD spikes allows to obtain accurate measurement results for a variety of nuclear materials under potentially difficult handling or measurement conditions. Because of expected difficulties in a stably long term supply of plutonium reference materials, which are the main source of plutonium for LSD spikes preparation, the JAEA's PFDC decided to evaluate the possibility of using domestically available MOX powders as a plutonium source material for LSD spikes. Therefore, PFDC started to separate, purify and characterize plutonium in MOX powders for plutonium reference materials (MOX-Pu) preparation that are suitable for source of LSD spikes in cooperation with the US DOE's NBL. The detailed preparation procedure of the latest MOX-Pu standard material and results of intercomparison for verification are presented.
Konda, Miki; Asai, Shiho; Hanzawa, Yukiko; Magara, Masaaki
JAEA-Technology 2015-054, 22 Pages, 2016/03
JAEA-Technology-2015-054.pdf:3.44MB
Isotope dilution mass spectrometry (IDMS) with ICP-MS is reliable method for determination of Zr-93, which is one of the long-lived fission products found in spent nuclear fuel and high-level radioactive wastes. In order to use an isotope standard solution of zirconium as the spike for IDMS, dissolving a commercially available solid isotope standard is indispensable. Prior to the dissolution of the Zr-91 isotope standard, solubility of metal zirconium in a mixture of HNO
and HF was evaluated using zirconium metal chips. Then, 2 mg of the Zr-91 isotope standard was dissolved with 0.2 mL of 1 M HNO-3 v/v% HF mixed solution, followed by adjusting the concentration of Zr-91 to approximately 1,000 
g/g. IDMS, in which a natural isotopic abundance standard solution of zirconium was used as the spike, was employed for the determination of the concentration of Zr-91 in the prepared Zr-91 isotope standard solution. The concentration of Zr-91 in the prepared Zr-91 isotope standard solution was (9.6
1.0) 
10
g/g, which is in good agreement with the predicted concentration. This indicates that the Zr-91 metal isotope standard was completely dissolved with sufficient chemical stability. Additionally, no impurities were detected in the prepared Zr-91 isotope standard solution. These positive results denote that the Zr-91 isotope standard solution with the preferable quality for IDMS of Zr-93 can be obtained by the proposed dissolution procedures.
Miyamoto, Yutaka
Hoshaka Bunseki Handobukku, 7 Pages, 2004/00
no abstracts in English
Takebe, Shinichi; Fujiwara, Keiji*; Moriyama, Hirotake*
Nihon Genshiryoku Gakkai "Shisetsu, Kankyo Hoshano Dotai" Kenkyu Senmon Iinkai Hokokusho, p.1 - 9, 2003/03
no abstracts in English
-factors for k-based neutron-induced prompt 
-ray analysisMatsue, Hideaki; Yonezawa, Chushiro
Journal of Radioanalytical and Nuclear Chemistry, 255(1), p.125 - 129, 2003/01
Times Cited Count：8 Percentile：49.89(Chemistry, Analytical)no abstracts in English
Hatsukawa, Yuichi; Toh, Yosuke; Oshima, Masumi; Hayakawa, Takehito; Shinohara, Nobuo; Kushita, Kohei; Ueno, Takashi; Toyoda, Kazuhiro*
Journal of Radioanalytical and Nuclear Chemistry, 255(1), p.111 - 113, 2003/01
Times Cited Count：12 Percentile：62.23(Chemistry, Analytical)no abstracts in English
Ishii, Toshimitsu
Hihakai Kensa, 51(6), p.328 - 332, 2002/06
no abstracts in English
Yoshizawa, Michio
Hokeikyo Nyusu, (29), p.2 - 5, 2002/05
no abstracts in English
-ray detectionOshima, Masumi; Toh, Yosuke; Hatsukawa, Yuichi; Hayakawa, Takehito; Shinohara, Nobuo
Journal of Nuclear Science and Technology, 39(4), p.292 - 294, 2002/04
Times Cited Count：18 Percentile：73.21(Nuclear Science & Technology)no abstracts in English
Hatsukawa, Yuichi; Oshima, Masumi; Hayakawa, Takehito; Toh, Yosuke; Shinohara, Nobuo
Nuclear Instruments and Methods in Physics Research A, 482(1-2), p.328 - 333, 2002/04
Times Cited Count：25 Percentile：81.52(Instruments & Instrumentation)no abstracts in English
; ; ; ; ; *; *
JNC TN8400 2001-026, 29 Pages, 2001/12
JNC-TN8400-2001-026.pdf:0.99MB
The measurement condition by spectrophotometry was evaluated to measure Np content in MOX fuel containing Np. The Np concentration was obtained by measuring the 727nm absorption peak, after the valence of Np in the sample solution was adjusted to the Np(Ⅳ). The calibration curve showed the linearity up to Np concentration 0.8mg/ml. Though Pu and U quantity were respectively added to the Np solution to 30 times and 60 times of Np concentration, there was no effect to the Np analysis. By using this method, relative standard deviation (RSD) of the analyzed values of Np content for 2%Np - MOX fuel was about 4%. In addition, It was confirmed that the Np content could be measured without separating Np from Pu and U. This method can be sufficiently applied as a quick simple method to analyze Np content in MOX fuel containing Np.
JNC TN1400 2001-015, 509 Pages, 2001/10
JNC-TN1400-2001-015.pdf:25.67MB
no abstracts in English
Saegusa, Jun
Hokeikyo Nyusu, (28), p.2 - 5, 2001/10
no abstracts in English
