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Journal Articles

Plasticity correction on stress intensity factor evaluation for underclad cracks in reactor pressure vessels

Lu, K.; Katsuyama, Jinya; Li, Y.

Journal of Pressure Vessel Technology, 142(5), p.051501_1 - 051501_10, 2020/10

 Times Cited Count:0 Percentile:0(Engineering, Mechanical)

Journal Articles

Thermal-hydraulic analysis of the LBE spallation target head in JAEA

Wan, T.; Obayashi, Hironari; Sasa, Toshinobu

Nuclear Technology, 205(1-2), p.188 - 199, 2019/01

 Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)

JAEA Reports

Confirmation tests for Warm Pre-stress (WPS) effect in reactor pressure vessel steel (Contract research)

Chimi, Yasuhiro; Iwata, Keiko; Tobita, Toru; Otsu, Takuyo; Takamizawa, Hisashi; Yoshimoto, Kentaro*; Murakami, Takeshi*; Hanawa, Satoshi; Nishiyama, Yutaka

JAEA-Research 2017-018, 122 Pages, 2018/03


Warm pre-stress (WPS) effect is a phenomenon that after applying a load at a high temperature fracture does not occur in unloading during cooling, and then the fracture toughness in reloading at a lower temperature increases effectively. Engineering evaluation models to predict an apparent fracture toughness in reloading are established using experimental data with linear elasticity. However, there is a lack of data on the WPS effect for the effects of specimen size and surface crack in elastic-plastic regime. In this study, fracture toughness tests were performed after applying load-temperature histories which simulate pressurized thermal shock transients to confirm the WPS effect. The experimental results of an apparent fracture toughness tend to be lower than the predictive results using the engineering evaluation models in the case of a high degree of plastic deformation in preloading. Considering the plastic component of preloading can refine the engineering evaluation models.

Journal Articles

Measurement of thermal deformation of magnetic alloy cores of radio frequency cavities in 3-GeV rapid-cycling synchrotron of Japan Proton Accelerator Research Complex

Shimada, Taihei; Nomura, Masahiro; Tamura, Fumihiko; Yamamoto, Masanobu; Sugiyama, Yasuyuki*; Omori, Chihiro*; Hasegawa, Katsushi*; Hara, Keigo*; Yoshii, Masahito*

Nuclear Instruments and Methods in Physics Research A, 875, p.92 - 103, 2017/12

 Times Cited Count:0 Percentile:0.02(Instruments & Instrumentation)

Journal Articles

Study on the thermal-hydraulic of TEF-T LBE spallation target in JAEA

Wan, T.; Obayashi, Hironari; Sasa, Toshinobu

Proceedings of 17th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-17) (USB Flash Drive), 13 Pages, 2017/09

Journal Articles

In-situ residual stress analysis during thermal cycle of a dissimilar weld joint using neutron diffraction and IEFEM

Akita, Koichi; Shibahara, Masakazu*; Ikushima, Kazuki*; Nishikawa, Satoru*; Furukawa, Takashi*; Suzuki, Hiroshi; Harjo, S.; Kawasaki, Takuro; Vladimir, L.*

Yosetsu Gakkai Rombunshu (Internet), 35(2), p.112s - 116s, 2017/06

Journal Articles

Derivation of simple evaluation method for thermal shock damage on accelerator materials caused by out-of-control beam pulses and its application to J-PARC

Takei, Hayanori; Kobayashi, Hitoshi*

Journal of Nuclear Science and Technology, 42(12), p.1032 - 1039, 2005/12

 Times Cited Count:3 Percentile:25.79(Nuclear Science & Technology)

In high-intensity proton accelerator facilities, a failure of an electromagnet that steers beam pulses may result in thermal shock damage on the accelerator component by injecting an out-of-control pulse. It is important that a Machine Protection System (MPS) is appropriately designed to prevent this damage in the facilities such as Japan Proton Accelerator Research Complex (J-PARC). In this study, the simple evaluation method for the allowable injection time before the operation of the MPS was derived from the relation between the thermal stress and the yield stress of materials.The derived evaluation method was then applied to J-PARC. The allowable injection time for each component ranged from 0.1 to 70 $$mu$$s.

Journal Articles

Effect of proton beam profile on stress in JSNS target vessel

Kogawa, Hiroyuki; Ishikura, Shuichi*; Sato, Hiroshi; Harada, Masahide; Takatama, Shunichi*; Futakawa, Masatoshi; Haga, Katsuhiro; Hino, Ryutaro; Meigo, Shinichiro; Maekawa, Fujio; et al.

Journal of Nuclear Materials, 343(1-3), p.178 - 183, 2005/08

 Times Cited Count:8 Percentile:51.68(Materials Science, Multidisciplinary)

A cross-flow type (CFT) mercury target with flow guide blades, which has been developed for JSNS, can suppress the generation of stagnant flow region especially near the beam window where the peak heat density is generated due to spallation reaction. Then, a flat type beam window has been applied to the CFT target from the viewpoint of suppressing dynamic stress caused by a pressure wave, which has been estimated with a mercury model of the linear equation of state. The recent experimental results obtained by using a proton beam incidents to mercury led that a cutoff pressure model in the equation of state of mercury caused a suitable dynamic stress with experimental results. Dynamic stress analyses were carried out with the cutoff pressure model, in which the negative pressure less than 0.15 MPa was not generated. The generated dynamic stress in the flat beam window became much larger than that in a semi-cylindrical type window. However, the generated stress in the semi-cylindrical type beam window was over the allowable stress of SS316L under the peak heat density of 668 W/cc. In order to decrease the dynamic stress in the semi-cylindrical beam window, the incident proton beam was defocused to decrease the peak heat density down to 218 W/cm$$^{3}$$. As a result, the dynamic stress could be suppressed less than the allowable stress. On the other hand, due to defocus of the proton beam, high heat density was generated on the end of the flow guide blades, which caused high thermal stress exceeding the allowable stress. To decrease the thermal stress, several shapes of the blade ends were studied analytically, which were selected so as not to affect the mercury flow distribution. A simple thin-end blade showed low thermal stress below the allowable stress.

Journal Articles

Development of Stress intensity factor coefficients database for a surface crack of an RPV considering the stress discontinuity between cladding and base metal

Onizawa, Kunio; Shibata, Katsuyuki*; Suzuki, Masahide

Proceedings of 2005 ASME/JSME Pressure Vessels and Piping Division Conference (PVP 2005), 12 Pages, 2005/07

Under a transient loading like pressurized thermal shock (PTS), the stress discontinuity near the interface between cladding and base metal of a reactor pressure vessel (RPV) is caused by the difference in their thermal expansion factors. So the stress intensity factor (SIF) of a surface crack which the deepest point exceeds the interface should be calculated by taking account of the stress discontinuity. Many SIF calculations are performed in Monte Carlo simulation of the probabilistic fracture mechanics (PFM) analysis. To avoid the time consuming process from the SIF calculation in the PFM analysis, the non-dimensional SIF coefficients corresponding to the stress distributions in the cladding and base metal were developed. The non-dimensional SIF coefficients database were obtained from 3D FEM analyses. The SIF value at the surface was determined by linear extrapolation of SIF value near the surface. Using the SIF coefficients database, the SIF values at both surface and deepest points of a surface crack can be evaluated precisely and in a reasonable time.

JAEA Reports

Failure probability analysis on mercury target vessel

Ishikura, Shuichi*; Shiga, Akio*; Futakawa, Masatoshi; Kogawa, Hiroyuki; Sato, Hiroshi; Haga, Katsuhiro; Ikeda, Yujiro

JAERI-Tech 2005-026, 65 Pages, 2005/03


Failure probability analysis was carried out to estimate the lifetime of the mercury target which will be installed into the JSNS (Japan spallation neutron source) in J-PARC (Japan Proton Accelerator Research Complex). The lifetime was estimated as taking loading condition and materials degradation into account. Considered loads imposed on the target vessel were the static stresses due to thermal expansion and static pre-pressure on He-gas and mercury and the dynamic stresses due to the thermally shocked pressure waves generated repeatedly at 25 Hz. Materials used in target vessel will be degraded by the fatigue, neutron and proton irradiation, mercury immersion and pitting damages, etc. The imposed stresses were evaluated through static and dynamic structural analyses. The material-degradations were deduced based on published experimental data. As results, it was quantitatively confirmed that the failure probability for the lifetime expected in the design is very much lower, 10$$^{-11}$$ in the safety hull, meaning that it will be hardly failed during the design lifetime. On the other hand, the beam window of mercury vessel suffered with high-pressure waves exhibits the failure probability of 12%. It was concluded, therefore, that the leaked mercury from the failed area at the beam window is adequately kept in the space between the safety hull and the mercury vessel to detect mercury-leakage sensors.

JAEA Reports

Review of JAERI activities on the IFMIF liquid lithium target in FY2004

Nakamura, Hiroo; Ida, Mizuho*; Matsuhiro, Kenjiro; Fischer, U.*; Hayashi, Takumi; Mori, Seiji*; Nakamura, Hirofumi; Nishitani, Takeo; Shimizu, Katsusuke*; Simakov, S.*; et al.

JAERI-Review 2005-005, 40 Pages, 2005/03


The International Fusion Materials Irradiation Facility (IFMIF) is being jointly planned to provide an accelerator-based Deuterium-Lithium (Li) neutron source to produce intense high energy neutrons (2 MW/m$$^{2}$$) up to 200 dpa and a sufficient irradiation volume (500 cm$$^{3}$$) for testing the candidate materials and components up to about a full lifetime of their anticipated use in ITER and DEMO. To realize such a condition, 40 MeV deuteron beam with a current of 250 mA is injected into high speed liquid Li flow with a speed of 20 m/s. In target system, radioactive species such as 7Be, tritium and activated corrosion products are generated. In addition, back wall operates under severe conditions of neutron irradiation damage (about 50 dpa/y). In this paper, the thermal and thermal stress analyses, the accessibility evaluation of the IFMIF Li loop, and the tritium inventory and permeation of the IFMIF Li loop are summarized as JAERI activities on the IFMIF target system performed in FY2004.

Journal Articles

JAERI 10kW high power ERL-FEL and its applications in nuclear energy industries

Minehara, Eisuke; Hajima, Ryoichi; Iijima, Hokuto; Kikuzawa, Nobuhiro; Nagai, Ryoji; Nishimori, Nobuyuki; Nishitani, Tomohiro; Sawamura, Masaru; Yamauchi, Toshihiko

Proceedings of 27th International Free Electron Laser Conference (FEL 2005) (CD-ROM), p.305 - 308, 2005/00

The JAERI high power ERL-FEL has been extended to the more powerful and efficient free-electron laser (FEL) than 10kW for nuclear energy industries, and other heavy industries like defense, shipbuilding, chemical industries, environmental sciences, space-debris, and power beaming and so on. In order to realize such a tunable, highly-efficient, high average power, high peak power and ultra-short pulse FEL, we need the efficient and powerful FEL driven by the JAERI compact, stand-alone and zero boil-off super-conducting RF linac with an energy-recovery geometry. Our discussions on the ERL-FEL will cover the current status of the 10kW upgrading and its applications of non-thermal peeling, cutting, and drilling to decommission the nuclear power plants, and to demonstrate successfully the proof of principle prevention of cold-worked stress-corrosion cracking failures in nuclear power reactors under routine operation using small cubic low-Carbon stainless steel samples.

Journal Articles

High temperature bending characteristics of Al$$_{2}$$O$$_{3}$$ joints bonded using superplastic ceramics as interlayer

Sato, Takashi*; Motohashi, Yoshinobu*; Sakuma, Takaaki*; Waseda, Kazuyoshi*; Shibata, Taiju; Ishihara, Masahiro; Sawa, Kazuhiro

Nihon Kikai Gakkai Kanto Shibu Ibaraki Koenkai (2004) Koen Rombunshu (No.040-3), p.55 - 56, 2004/09

no abstracts in English

JAEA Reports

Structural integrity of heavy liquid-metal target installed in spallation neutron facility, 4; Consideration by fracture mechanics of target container window

Ishikura, Shuichi*; Kogawa, Hiroyuki; Futakawa, Masatoshi; Kikuchi, Kenji; Haga, Katsuhiro; Kaminaga, Masanori; Hino, Ryutaro

JAERI-Tech 2003-093, 55 Pages, 2004/01


To estimate the structural integrity of the heavy liquid-metal (Hg) target used in a MW-class neutron scattering facility, static and dynamic stress behaviors due to the incident of a 1MW-pulsed proton beam were analyzed. In the analyses, two-type target containers with semi-cylindrical type and flat type window were used as analytical models of the structural analysis codes LS-DYNA. As a result, it is confirmed that the stress generated by dynamic thermal shock becomes the largest at the center of window, and the flat type window is more advantageous from the structural viewpoint than the semi-cylindrical type window. It was confirmed to erosion damage the target container by mercury's becoming negative pressure in the window and generating the cavitation by the experiment. Therefore, it has been understood that the point top of the window was in the compression stress field by the steady state thermal stress because of the evaluation from destroying the dynamic viewpoint for the crack in the generated pit and the pit point, and the crack did not progress.

JAEA Reports

Development of probabilistic fracture mechanics code PASCAL and user's manual

Shibata, Katsuyuki; Onizawa, Kunio; Li, Y.*; Kato, Daisuke*

JAERI-Data/Code 2001-011, 233 Pages, 2001/03


no abstracts in English

Journal Articles

Inertia effect on thermal shock by laser beam shot

Kogawa, Hiroyuki; Futakawa, Masatoshi; Ishikura, Shuichi*; Kikuchi, Kenji; Hino, Ryutaro; Eto, Motokuni

International Journal of Impact Engineering, 25(1), p.17 - 28, 2001/01

 Times Cited Count:3 Percentile:24.83(Engineering, Mechanical)

no abstracts in English

JAEA Reports

Design of ITER shielding blanket

Furuya, Kazuyuki; Sato, Satoshi; Hatano, Toshihisa; *; Kitamura, Kazunori*; Miura, H.*; *; Kuroda, Toshimasa*; Takatsu, Hideyuki

JAERI-Tech 97-022, 113 Pages, 1997/05


no abstracts in English

JAEA Reports

Transient thermal and stress analyses of the ITER shielding blanket/first wall under off-normal conditions

Furuya, Kazuyuki; Hashimoto, T.*; Sato, Satoshi; Kuroda, Toshimasa*; *; Kurasawa, Toshimasa; *; Takatsu, Hideyuki

JAERI-Tech 95-045, 53 Pages, 1995/09


no abstracts in English

Journal Articles

Three-dimensional thermal stress numerical convergence analysis of a hot spot in a thin pipe using the boundary element method

Bains, R.S.*; Sugimoto, Jun

Engineering Analysis with Boundary Elements, 14, p.267 - 275, 1994/00

 Times Cited Count:4 Percentile:76.68(Engineering, Multidisciplinary)

no abstracts in English

Journal Articles

Thermal response experiments of SiC/C and TiC/C functionally gradient materials as plasma facing materials for fusion application

Araki, Masanori; *; S.Kim*; ; Nakamura, Kazuyuki; Akiba, Masato

Journal of Nuclear Materials, 212-215, p.1329 - 1334, 1994/00

 Times Cited Count:10 Percentile:67.24(Materials Science, Multidisciplinary)

no abstracts in English

36 (Records 1-20 displayed on this page)