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Nagase, Fumihisa; Fuketa, Toyoshi
Journal of Nuclear Science and Technology, 42(1), p.58 - 65, 2005/01
Times Cited Count：47 Percentile：92.75(Nuclear Science & Technology)Tube burst tests have been performed with artificially hydrided Zircaloy-4 specimens at room temperature and at 620 K. Pressurization rate was increased to a maximum of 3.4 GPa/s in order to simulate rapid PCMI that occurs in high burnup fuel rods during a pulse-irradiation in the NSRR. Hydrogen content in the specimens ranged from 150 to 1050 ppm. Hydrides were accumulated in the cladding periphery and formed "hydride rim" as observed in high burnup PWR fuel claddings. The hydrided cladding tubes failed with an axial crack at the room temperature tests. Brittle fracture appeared in the hydride rim, and failure morphology was similar to that observed in the NSRR experiments. The hydrides rim obviously reduced burst pressure and residual hoop strain at the tests. The residual hoop strain was very small even at 620 K when thickness of the hydride rim exceeded 18% of cladding thickness. The present result accordingly indicates an important role of the hydrides layer in high burnup fuel rod failure under RIA conditions.
Nagase, Fumihisa; Fuketa, Toyoshi
Journal of Nuclear Science and Technology, 41(12), p.1211 - 1217, 2004/12
Times Cited Count：19 Percentile：75.21(Nuclear Science & Technology)Hydride precipitation along the radial-axial plane increases in high burn-up BWR fuel claddings. The radial hydrides may have an important role during fuel behavior in a RIA and may reduce ductility of the cladding under PCMI conditions. In order to promote a better understanding of the influence of the radial hydrides on cladding failure behavior under the PCMI conditions, tube burst tests were conducted for unirradiated BWR claddings charged with 200 to 650 ppm of hydrogen. About 20 to 30% of hydrides were re-oriented and precipitated along the radial-axial plane. The claddings exhibited large burst openings with an axial crack at room temperature and 373 K. However, the influence of the radial hydrides on both burst pressure and residual hoop strain was very small. It is accordingly expected that ductility of high burn-up BWR cladding is significantly reduced not only by precipitation of radial hydrides as far as hydrogen concentration and radial hydride fraction range in the present study.
Nagase, Fumihisa; Otomo, Takashi; Uetsuka, Hiroshi
JAERI-Research 2000-046, 31 Pages, 2000/12
JAERI-Research-2000-046.pdf:3.72MB
no abstracts in English
Otomo, Takashi; Nagase, Fumihisa; Uetsuka, Hiroshi
JAERI-Tech 99-071, p.25 - 0, 1999/10
no abstracts in English
Nagase, Fumihisa; ; Uetsuka, Hiroshi
JAERI-Research 98-064, 25 Pages, 1998/11
JAERI-Research-98-064.pdf:2.17MB
no abstracts in English
