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Onizawa, Kunio; Shibata, Katsuyuki; Kato, Daisuke*; Li, Y.*
JSME International Journal, Series A, 47(3), p.486 - 493, 2004/07
The probabilistic fracture mechanics (PFM) analysis code PASCAL has been developed in JAERI. This code can evaluate the conditional probabilities of crack initiation and fracture of a reactor pressure vessel (RPV) under transient conditions such as pressurized thermal shock (PTS). Based on the temperature and stress distributions in the vessel wall for four PTS sequences in a typical 3-loop PWR, parametric PFM analyses are performed using PASCAL on the variables such as pre-service inspection model, crack geometry, fracture toughness curve and irradiation embrittlement prediction equation. The results showed that the good perfomance inspection model had a significant effect on the fracture probability and reduced it by more than 3 orders of magnitude. The fracture probability calculated by the fracture toughness estimation method in Japan was about 2 orders of magnitude lower than that by the USA method. It was found that the treatment of a semi-elliptical crack in PASCAL reduced the conservatism in a conventional method that it is transformed into an infinite length crack.
Nakahira, Masataka
Journal of Nuclear Science and Technology, 40(9), p.687 - 694, 2003/09
Times Cited Count：3 Percentile：25.75(Nuclear Science & Technology)The ITER vacuum vessel is a double-walled torus with large-sized quadrilateral ports and is required to provide a quite high degree of vacuum for deutrium - tritium fusion reaction. The vacuum vessel is required to install after assembled with toroidal field coils. From a radiological safety aspect, the vacuum vessel is functioned as a physical barrier to enclose radioactive materials. Therefore, construction of the vacuum vessel needs application of newly developed technologies on design, fabrication and examination. The technologies include design approach by finite element analysis, and partial penetration T welded joints to join ribs to outer shell. Several issues have to be resolved for applying those technologies to the vacuum vessel. This paper describes several newly developed technologies and key issues for applying to the vacuum vessel and then their resolutions.
Onizawa, Kunio; Shibata, Katsuyuki; Kato, Daisuke*; Li, Y.*
Proceedings of 11th International Conference on Nuclear Engineering (ICONE-11) (CD-ROM), 8 Pages, 2003/04
Probabilistic Fracture Mechanics (PFM) has been used in the fields of reliability analysis for important structural components. At JAERI, the PFM analysis code PASCAL has been developed. This code evaluates the conditional probabilities of crack initiation and fracture of a reactor pressure vessel (RPV) under transient conditions such as pressurized thermal shock (PTS). Four cases of PTS transients were selected based on the severity for a typical 3-loop PWR. Based on thermal stress analyses, PFM analyses were performed by using PASCAL code focusing on some important variables on the RPV fracture probability. The results showed that non-destructive examination methods had a significant effect on the fracture probability by more than three orders of magnitude. The comparisons of the results using fracture toughness estimation methods between in Japan and USA, and crack geometries between a semi-elliptical surface crack and an infinite surface crack are also made.
Ezato, Koichiro; Dairaku, Masayuki; Taniguchi, Masaki; Sato, Kazuyoshi; Akiba, Masato
Journal of Nuclear Materials, 307-311(Part1), p.144 - 148, 2002/12
Times Cited Count：14 Percentile：65.5(Materials Science, Multidisciplinary)no abstracts in English
Kosaku, Yasuo; Kuroda, Toshimasa*; Enoeda, Mikio; Hatano, Toshihisa; Sato, Satoshi; Akiba, Masato
JAERI-Tech 2002-063, 98 Pages, 2002/07
JAERI-Tech-2002-063.pdf:11.16MB
no abstracts in English
Nishiyama, Yutaka; Fukaya, Kiyoshi; Suzuki, Masahide; Eto, Motokuni; *
Small Specimen Test Techniques; ASTM STP 1204, p.16 - 26, 1993/00
no abstracts in English
