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Kai, Tetsuya; Harada, Masahide; Teshigawara, Makoto; Watanabe, Noboru; Ikeda, Yujiro
Nuclear Instruments and Methods in Physics Research A, 523(3), p.398 - 414, 2004/05
Times Cited Count：36 Percentile：89.15(Instruments & Instrumentation)Neutronic performance of a coupled hydrogen moderator was studied as a function of para hydrogen concentration, moderator thickness, height and premoderator thickness. It was found that a thick (120
140mm) moderator with 100% para hydrogen was optimal to provide the highest time- and energy- integrated neutron intensity below 15 meV together with the highetst possible pulse-peak intensity. Low-energy neutron distribution on the moderator viewed surface was found to exhibit an intensity-enhanced region at a picture frame part near premoderator. The rather peculiar distribution suggested that the moderator and the viewed surface must be designed so as to take the brighter region near premoderator in use.
Nagase, Fumihisa; Uetsuka, Hiroshi
JAERI-Research 2002-023, 23 Pages, 2002/11
JAERI-Research-2002-023.pdf:1.94MB
To obtain basic data to evaluate fuel rod integrity during abnormal transient and accident of LWRs, high burnup PWR fuel claddings were heated for 0 to 600s at temperatures of 673 through 1173K, and the mechanical property changes were examined by using ring tensile test at room temperature. As a result of the test, it was shown that strength and ductility of the cladding are changed depending on heating temperature and time. The mechanical property changes by temperature transients are considered to be correspondent mainly to recovery of irradiation defect, recovery and recrystallization of the Zircaloy, phase transformations, and associated change of the hydride distribution and morphology. Comparison with unirradiated claddings suggested that irradiation effects are not completely annealed out by the short-term annealing at high temepratures. Radial change of hydrogen concentration was measured for the high burnup PWR fuel cladding and very high hydrogen concentration of about 2400wtppm was detected at the cladding periphery.
Nishihara, Tetsuo; Hada, Kazuhiko
Nihon Genshiryoku Gakkai-Shi, 41(5), p.571 - 578, 1999/05
Times Cited Count：5 Percentile：40.57(Nuclear Science & Technology)no abstracts in English
solution by electrodialysisOnuki, Kaoru; Nakajima, Hayato; Shimizu, Saburo
Kagaku Kogaku Rombunshu, 23(2), p.289 - 291, 1997/00
Times Cited Count：5 Percentile：42.32(Engineering, Chemical)no abstracts in English
Noguchi, Hiroshi; Murata, Mikio
Nihon Genshiryoku Gakkai-Shi, 33(4), p.360 - 362, 1991/04
Times Cited Count：2 Percentile：51.20(Nuclear Science & Technology)no abstracts in English
Saeki, Masakatsu; Nakashima, Mikio; ; Tachikawa, Enzo
Journal of Nuclear Materials, 120, p.267 - 271, 1984/00
Times Cited Count：3 Percentile：38.11(Materials Science, Multidisciplinary)no abstracts in English
Hirabayashi, Masaru; Ara, Kuniaki; Hino, Ryutaro
no journal, ,
Since existing hydrogen monitors cannot be used with the sampling method in severe accident conditions, a new type hydrogen monitor by using acoustic technique is under development. The measurement principle that the sound velocity is changed according to the hydrogen concentration in a mixed gas is utilized for the new type monitor. In the basic performance tests, it was confirmed that the hydrogen concentration could be measured in a high accuracy. Also, influence of environment conditions was evaluated.
