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Murakami, Kenta*; Arai, Taku*; Yamada, Koji*; Momma, Kensuke*; Tsuji, Takashi*; Nakagawa, Nobuyuki*; Onizawa, Kunio
Transactions of the 27th International Conference on Structural Mechanics in Reactor Technology (SMiRT 27) (Internet), 3 Pages, 2024/03
This paper studied the future vision of codes and standards in Japan by systematically comparing Japanese regulatory rules, standards, and industry guides related to long term operation with international safety standards, and confirmed that the Japanese standard system generally meets their recommendations. The recommendation for the future improvements of Japanese codes and standards were summarized into five items.
Tominaga, Taiki*; Nakagawa, Hiroshi; Sahara, Masae*; Oda, Takashi*; Inoue, Rintaro*; Sugiyama, Masaaki*
Life (Internet), 12(5), p.675_1 - 675_9, 2022/05
Times Cited Count:0 Percentile:0.01(Biology)The background scattering of sample cells suitable for aqueous protein solution samples, conducted with a neutron backscattering spectrometer, was evaluated. It was found that the scattering intensity of an aluminum sample cell coated with boehmite using DO was lower than that of a sample cell coated with regular water (HO). In addition, meticulous attention to cells with small individual weight differences and the positional reproducibility of the sample cell relative to the spectrometer neutron beam position enabled the accurate subtraction of the scattering profiles of the DO buffer and the sample container. Consequently, high quality information on protein dynamics could be extracted from dilute protein solutions.
Miura, Daisuke*; Kumada, Takayuki; Sekine, Yurina; Motokawa, Ryuhei; Nakagawa, Hiroshi; Oba, Yojiro; Ohara, Takashi; Takata, Shinichi; Hiroi, Kosuke; Morikawa, Toshiaki*; et al.
Journal of Applied Crystallography, 54(2), p.454 - 460, 2021/04
Times Cited Count:1 Percentile:17.63(Chemistry, Multidisciplinary)We developed a spin-contrast-variation neutron powder diffractometry technique that extracts the structure factor of hydrogen atoms, namely, the contribution of hydrogen atoms to a crystal structure factor. Crystals of L-glutamic acid were dispersed in a dpolystyrene matrix containing 4-methacryloyloxy-2,2,6,6,-tetramethyl-1-piperidinyloxy (TEMPO methacrylate) to polarize their proton spins dynamically. The intensities of the diffraction peaks of the sample changed according to the proton polarization, and the structure factor of the hydrogen atoms was extracted from the proton-polarization dependent intensities. This technique is expected to enable analyses of the structures of hydrogen-containing materials that are difficult to determine with conventional powder diffractometry.
Inoue, Rintaro*; Oda, Takashi*; Nakagawa, Hiroshi; Tominaga, Taiki*; Saio, Tomohide*; Kawakita, Yukinobu; Shimizu, Masahiro*; Okuda, Aya*; Morishima, Ken*; Sato, Nobuhiro*; et al.
Scientific Reports (Internet), 10, p.21678_1 - 21678_10, 2020/12
Times Cited Count:3 Percentile:13.48(Multidisciplinary Sciences)Incoherent quasielastic neutron scattering (iQENS) is a fascinating technique for investigating the internal dynamics of protein. However, both low flux of neutron beam and absence of analytical procedure for extracting the internal dynamics from iQENS profile have been obstacles for studying it under physiological condition (in solution). Thanks to the recent development of neutron source, spectrometer and computational technique, they enable us to decouple internal dynamics, translational and rotational diffusions from the iQENS profile. The internal dynamics of two proteins: globular domain protein (GDP) and intrinsically disordered protein (IDP) in solution were studied. It was found that the average relaxation rate of IDP was larger than that of GDP. Through the detailed analyses on their internal dynamics, it was revealed that the fraction of mobile H atoms in IDP was much higher than that in GDP. Interestingly, the fraction of mobile H atoms was closely related to the fraction of H atoms on highly solvent exposed surfaces. The iQENS study presented that the internal dynamics were governed by the highly solvent exposed amino acid residues depending upon protein molecular architectures.
Meguro, Yoshihiro; Nakagawa, Akinori; Kato, Jun; Sato, Junya; Nakazawa, Osamu; Ashida, Takashi
Proceedings of International Conference on the Safety of Radioactive Waste Management (Internet), p.139_1 - 139_4, 2016/11
A variety of radioactive wastes have been generated in decommissioning of Fukushima Daiichi Nuclear Power Station. It is necessary to evaluate feasibility of conditioning methods to these wastes, because the majority of such wastes have not been solidified in Japan. The authors investigated an approach for screening of conditioning methods for the Fukushima wastes on the basis of the findings of the existing methods and results of fundamental solidification tests using synthetic Fukushima wastes. Here five solidification methods were selected, and also 13 wastes with different chemical composition are solidified, and characteristics of the solidified form are studied. A screening flow was proposed, and evaluation criteria on each step in the flow was set up. In this presentation a trial result was opened for a waste and improvements of the screening flow found in the trial evaluation was described.
Takahashi, Akihisa*; Kubo, Makoto*; Ma, H.*; Nakagawa, Akiko*; Yoshida, Yukari*; Isono, Mayu*; Kanai, Tatsuaki*; Ono, Tatsuya*; Furusawa, Yoshiya*; Funayama, Tomoo; et al.
Radiation Research, 182(3), p.338 - 344, 2014/09
Times Cited Count:57 Percentile:90.66(Biology)To clarify whether high-LET radiation inhibits all repair pathways or specifically one repair pathway, studies were designed to examine the effects of radiation with different LET values on DNA DSB repair and radiosensitivity. Embryonic fibroblasts bearing repair gene KO were exposed to X rays, carbon-, iron-, neon- and argon-ion beams. Cell survival was measured with colony-forming assays. The sensitization enhancement ratio (SER) values were calculated using the 10% survival dose of wild-type cells and repair-deficient cells. Cellular radiosensitivity was listed in descending order: double-KO cells NHEJ-KO cells HR-KO cells wild-type cells. Although HR-KO cells had an almost constant SER value, NHEJ-KO cells showed a high-SER value when compared to HR-KO cells, even with increasing LET values. These results suggest that with carbon-ion therapy, targeting NHEJ repair yields higher radiosensitivity than targeting homologous recombination repair.
Irisawa, Keita; Nakagawa, Akinori; Onizawa, Takashi*; Kogawara, Takafumi*; Hanada, Keiji; Meguro, Yoshihiro
Proceedings of 15th International Conference on Environmental Remediation and Radioactive Waste Management (ICEM 2013) (CD-ROM), 5 Pages, 2013/09
Times Cited Count:1 Percentile:60.76(Engineering, Environmental)Nakagawa, Masahiro; Nojima, Shun; Fujii, Katsutoshi; Shishido, Nobuhito; Sakai, Toshiya; Umehara, Takashi; Shimizu, Isamu
Hoken Butsuri, 47(3), p.189 - 193, 2012/10
It is essential to wear an air-purifying respirator in the radiation works in a contaminated atmosphere. A breath-responsive-powered air-purifying respirator (BR-PAPR) has been recently developed. However, no research has yet been conducted to determine the protection factor (PF) of the BR-PAPR in actual workplaces. In this study, the PFs of the BR-PAPR were measured by a man-test apparatus and compared with those of a non-powered full face mask. The PFs were measured under three different situations; normal wearing condition, clogging the filter and leaving a gap between the face and the mask. Under these situations, it was found that the PFs of the BR-PAPR are higher than those of the non-powered full face mask. PFs greater than 4000 were obtained for 95% of the subjects who wear the BR-PAPR, and PFs over 6667, the upper limit of the man-test apparatus, were obtained for 49% of them. The questionnaire survey was conducted for workers. The results showed that the workers feel a reduced burden when they wear the BR-PAPR. The results of this study showed high protection performance and operation efficiency of the BR-PAPR.
Shibata, Akira; Nakano, Junichi; Omi, Masao; Kawamata, Kazuo; Nakagawa, Tetsuya; Tsukada, Takashi
Journal of Nuclear Materials, 422(1-3), p.14 - 19, 2012/03
Times Cited Count:0 Percentile:0.01(Materials Science, Multidisciplinary)To simulate Irradiation assisted stress corrosion cracking (IASCC) behavior by in-pile experiments, it is necessary to irradiate specimens up to a neutron fluence that is higher than the IASCC threshold fluence. Pre-irradiated specimens must be relocated from pre-irradiation capsules to in-pile capsules. Hence, a remote welding machine has been developed. And the integrity of capsule housing for a long term irradiation was evaluated by tensile tests in air and slow strain rate tests in water. Two type specimens were prepared. Specimens were obtained from the outer tubes of capsule irradiated to 1.0-3.9 10 n/m (E 1 MeV). And specimens were irradiated in a leaky capsule to 0.03-1.0 10 n/m. Elongation more than 15% in tensile test at 423 K was confirmed and no IGSCC fraction was shown in SSRT at 423 K which was estimated as temperature at the outer tubes of the capsule under irradiation.
Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Armendariz, R.*; et al.
Physical Review C, 83(6), p.064903_1 - 064903_29, 2011/06
Times Cited Count:184 Percentile:99.44(Physics, Nuclear)Transverse momentum distributions and yields for , and in collisions at = 200 and 62.4 GeV at midrapidity are measured by the PHENIX experiment at the RHIC. We present the inverse slope parameter, mean transverse momentum, and yield per unit rapidity at each energy, and compare them to other measurements at different collisions. We also present the scaling properties such as and scaling and discuss the mechanism of the particle production in collisions. The measured spectra are compared to next-to-leading order perturbative QCD calculations.
Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Aramaki, Y.*; et al.
Physical Review C, 83(4), p.044912_1 - 044912_16, 2011/04
Times Cited Count:8 Percentile:49.7(Physics, Nuclear)Measurements of electrons from the decay of open-heavy-flavor mesons have shown that the yields are suppressed in Au+Au collisions compared to expectations from binary-scaled collisions. Here we extend these studies to two particle correlations where one particle is an electron from the decay of a heavy flavor meson and the other is a charged hadron from either the decay of the heavy meson or from jet fragmentation. These measurements provide more detailed information about the interaction between heavy quarks and the quark-gluon matter. We find the away-side-jet shape and yield to be modified in Au+Au collisions compared to collisions.
Shibata, Akira; Nakano, Junichi; Omi, Masao; Kawamata, Kazuo; Saito, Takashi; Hayashi, Koji; Saito, Junichi; Nakagawa, Tetsuya; Tsukada, Takashi
Proceedings of 16th International Conference on Nuclear Engineering (ICONE-16) (CD-ROM), 8 Pages, 2008/05
Irradiation assisted stress corrosion cracking (IASCC) is considered to be one of the key issues in the aged Light Water Reactors. To simulate IASCC behavior by the in-pile or post-irradiation experiment, it is necessary to irradiate specimens up to a neutron fluence that is higher than the so-called IASCC threshold fluence. There are, however, some technical hurdles to be overcome for the experiments. The techniques assembling pre-irradiated specimens into a in-pile test capsule in a hot cell and the eveluation of material integrity of the capsule during a long term irradiation are necessary. To evaluate material integrity on capsules during a long term irradiation, tensile test and SSRT using specimens which was previously irradiated to 1.03.910 n/m were performed. In this paper, technical developments required for IASCC test, e.g. the development of assembling techniques for IASCC capsules and the evaluation of stainless steels which dosed high-fluence neutron were described.
Takada, Yukio*; Nakagawa, Takashi*; Tokunaga, Masatoshi*; Fukuta, Yasunari*; Tanaka, Takayoshi*; Yamamoto, Takao*; Tachibana, Takeshi*; Kawano, Shinji*; Ishii, Yoshinobu; Igawa, Naoki
Journal of Applied Physics, 100(4), p.043904_1 - 043904_7, 2006/08
Times Cited Count:71 Percentile:89.24(Physics, Applied)no abstracts in English
Takada, Yukio*; Nakagawa, Takashi*; Fukuta, Yasunari*; Tokunaga, Masatoshi*; Yamamoto, Takao*; Tachibana, Takeshi*; Kawano, Shinji*; Igawa, Naoki; Ishii, Yoshinobu
Japanese Journal of Applied Physics, 44(5A), p.3151 - 3156, 2005/05
Times Cited Count:3 Percentile:13.7(Physics, Applied)We investigated the correlation between the thremomagnetic curve of CoZ-Type hexagonal barium ferrite, BaCoFeO and its magnetic moment direction. The thermomagnetic curve shows two significant magnetization slumps at 540K and 680K. High-temperature neutron diffraction experiment and Rietveld analyses indicate that temperature rise from 523 to 573K makes the magnetic moments turn to the c-axis from a direction parallel to the c-plane most significantly.The change in average orientation of the magnetic moments must be induced by the disappearence of the contribution of cobalt to magnetism in this temperature.
Fumizawa, Motoo; Kameda, Atsuyuki*; Nakagawa, Takashi*; Wu, W.*; Yoshikawa, Hidekazu*
Nuclear Technology, 141(1), p.78 - 87, 2003/01
Times Cited Count:5 Percentile:36.81(Nuclear Science & Technology)no abstracts in English
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.
Kawai, Masayoshi*; Nakagawa, Tsuneo; Watanabe, Takashi*; Nakajima, Yutaka*; Zukeran, Atsushi*; Matsunobu, Hiroyuki*; Sugi, Teruo*; Chiba, Satoshi
Journal of Nuclear Science and Technology, 38(4), p.261 - 269, 2001/04
no abstracts in English
Nose, Tadao*; Matsumura, Akira*; Yamamoto, Tetsuya*; Shibata, Yasushi*; Yoshida, Fumiyo*; Akutsu, Hiroyoshi*; Yasuda, Susumu*; Matsushita, Akira*; Nakai, Kei*; Yamada, Takashi*; et al.
UTRCN-G-29, p.114 - 123, 2001/00
no abstracts in English
Matsumura, Akira*; Yamamoto, Tetsuya*; Shibata, Yasushi*; Akutsu, Hiroyoshi*; Yasuda, Susumu*; Matsushita, Akira*; Nakai, K.*; Yamada, Takashi*; Takano, Shingo*; Mizutani, Taro*; et al.
Proceedings of 9th International Symposium on Neutron Capture Therapy for Cancer, p.29 - 30, 2000/10
no abstracts in English
Nakagawa, Tsuneo; Watanabe, Takashi*; *
JAERI-Data/Code 97-050, 103 Pages, 1997/12
no abstracts in English