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Goux, P.*; Glessgen, F.*; Gazzola, E.*; Singh Reen, M.*; Focillon, W.*; Gonin, M.*; Tanaka, Tomoyuki*; Hagiwara, Kaito*; Ali, A.*; Sudo, Takashi*; et al.
Progress of Theoretical and Experimental Physics (Internet), 2023(6), p.063H01_1 - 063H01_15, 2023/06
Times Cited Count：0 Percentile：0.01(Physics, Multidisciplinary)
clusters in dilute neutron-rich matterTanaka, Junki*; Yang, Z.*; Typel, S.*; Adachi, Satoshi*; Bai, S.*; van Beek, P.*; Beaumel, D.*; Fujikawa, Yuki*; Han, J.*; Heil, S.*; et al.
Science, 371(6526), p.260 - 264, 2021/01
Times Cited Count：50 Percentile：99.36(Multidisciplinary Sciences)By employing quasi-free -cluster-knockout reactions, we obtained direct experimental evidence for the formation of clusters at the surface of neutron-rich tin isotopes. The observed monotonous decrease of the reaction cross sections with increasing mass number, in excellent agreement with the theoretical prediction, implies a tight interplay between -cluster formation and the neutron skin.
-wave one-neutron halo configuration on 
MgKobayashi, Nobuyuki*; Nakamura, Takashi*; Kondo, Yosuke*; Tostevin, J. A.*; Utsuno, Yutaka; Aoi, Nori*; Baba, Hidetada*; Barthelemy, R.*; Famiano, M. A.*; Fukuda, Naoki*; et al.
Physical Review Letters, 112(24), p.242501_1 - 242501_5, 2014/06
Times Cited Count：90 Percentile：94.35(Physics, Multidisciplinary)no abstracts in English
Naganawa, Hirochika; Kumazawa, Noriyuki*; Saito, Hiroshi*; Yanase, Nobuyuki; Mitamura, Hisayoshi; Nagano, Tetsushi; Kashima, Kaoru*; Fukuda, Tatsuya*; Yoshida, Zenko; Tanaka, Shunichi*
Nihon Genshiryoku Gakkai Wabun Rombunshi, 10(4), p.227 - 234, 2011/12
no abstracts in English
NeNakamura, Takashi*; Kobayashi, Nobuyuki*; Kondo, Yosuke*; Sato, Yoshiteru*; Aoi, Nori*; Baba, Hidetada*; Deguchi, Shigeki*; Fukuda, Naoki*; Gibelin, J.*; Inabe, Naoto*; et al.
Physical Review Letters, 103(26), p.262501_1 - 262501_4, 2009/12
Times Cited Count：198 Percentile：97.52(Physics, Multidisciplinary)no abstracts in English
-ray bursts and extremely metal-poor stars; Black hole-forming supernovae with relativistic jetsTominaga, Nozomu*; Maeda, Keiichi*; Umeda, Hideyuki*; Nomoto, Kenichi*; Tanaka, Masaomi*; Iwamoto, Nobuyuki; Suzuki, Tomoharu*; Mazzali, P. A.*
Astrophysical Journal, 657(2, Part2), p.L77 - L80, 2007/03
Times Cited Count：116 Percentile：91.9(Astronomy & Astrophysics)Long-duration -ray bursts (GRBs) are thought to be connected with luminous and energetic Type Ic supernovae [SNe, called hypernovae (HNe)] resulting from the black-hole (BH) forming collapse of massive stars. For GRBs 060505 and 060614, however, the expected SNe have not been detected. The upper limits to the SN brightness are about 100 times fainter than GRB-associated HNe (GRB-HNe), corresponding to the upper limits to the ejected 
Ni masses of 
Ni)
. SNe with a small amount of Ni ejection are observed as faint Type II SNe. HNe and faint SNe are thought to be responsible for the formaion of extremely metal-poor (EMP) stars. A relativistic jet-induced BH forming explosion of the 40
star is investigated and hydrodynamic and nucleosynthetic models are presented. These models can explain both GRB-HNe and GRBs without bright SNe in a unified manner. We suggest that GRBs without bright SNe are likely to synthesize Ni)
or 
.
; Wakai, Takashi; ; ; ;
PNC TN9410 93-220, 112 Pages, 1993/09
This report describes elastic thermal stress analysis and creep-fatigue damage estimation results of Mod.9Cr-1Mo piping specimen which consists of three different thickness portions (20, 15, 10mm), and contains six circumferential weldments. Thermal fatigue failure test on the specimen has been conducted in the sodium test loop named SPTT to clarify fatigue crack initiation behavior under thermal bending stress conditions, which is caused by temperature gradient arisen in the wall thickness of the specimen. The thermal transient test is now underway, with the condition where sodium of 550
C and 300C sodium alternately flow into the specimen for 5 minutes in one cycle. The test is scheduled to complete after loading 9,000 cycles of thermal transients. Crack inspection by using penetration test tequnique is planned after the test. For an analytical study, heat transfer analysis using measured temperature data and elastic thermal stress analysis were carried out with the finite element method, and the analysis results were utilized to develop a candidate creep-fatigue damage evaluation method for Mod.9Cr-1Mo steels based on elastic analysis. Some analysis and damage estimation results of the specimen are presented here, and crack initiation after 9,000 cycles of thermal transients are predicted based on the calculated creep-fatigue damage.
; Wakai, Takashi; ; ; ;
PNC TN9410 93-209, 115 Pages, 1993/09
This report describes elastic thermal stress analysis and creep-fatiguedamage evaluation results of an SUS316FR piping specimen which contains circumferential weldment in the middle portion of it. Thermal creep-fatigue failure test on the specimen was conducted in a sodiumtest loop named STST to clarify creep-fatigue crack initiation behavior of SUS316FR base metal and weldment under thermal bending stress conditions, which is caused by temperature gradient arisen in the wall thickness or the specimen. Thermal transient test was conducted under the condition that 550C and 300C sodium alternately flow into the specimen for 5 hours and 1 hour, respectively in one cycle. The test had been completed after loading 1,600 cycles or thermal transients. After the test, crack inspection by PT was performed, and cracks were observed successfully in both the base metal and weldment. For an analytical study, heat transfer analysis using measured temperature data and elastic thermal stress analysis were carried out with the finite element method, and the analysis results were utilized to develop a candidate creep-fatigue damage evaluation method for SUS316FR steel based on elasticanalysis. Some analysis results and damage evaluation results of the specimen arepresented here, and crack initiation after 1,600 cycles of thermal transients is predicted based on the calculated creep-fatigue damage, which demonstrates a good agreements with the crack distribution on the specimen inner surface.
Umeda, Hisao; Tanaka, Nobuyuki; Watashi, Katsumi; Kikuchi, Masayuki; Iwata, Koji
Nuclear Engineering and Design, 140, p.349 - 372, 1993/06
None
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PNC TN9410 92-217, 129 Pages, 1992/06
This report describes fracture parameter analysis results for the simplified crack growth analysis code "CANIS-G". Dimensionless stress intensity factor; K of the semi-elliptical surface cracks axially located in the inner surface of the cylinder with the thickness of 0.4 in t/r, here t; thickness of the cylinder and r; inner diameter. The shape and dimension of the surface cracks are ranged from 0.1 to 0.8 in a/t, and 0.2 to 1.0 in a/b, here a; crack depth and b; crack surface rength. Blastic stress analyses with the condition of constant, linear, quadratic and cubic stress distribution on the crack surface were performed by FINAS computer code. Stress intensity factor; K was calculated with the fracture parameter analysis code "CANIS-J" using the elastic analysis results, and was transformed to dimensionless stress intensity factor;F. As the result, calculated F values were considered to be reasonable compared with the F values formerly obtained by SHIRATORl under the condition of 0.1 in t/r. So, the newly obtained F values were installed within the fracture parameter data-base of the simplified crack growth analysis code 'CANIS-G'.
; ; ; ;
PNC TN9410 92-284, 229 Pages, 1992/05
This report describes the inelastic thermal stress analysis and creep-fatigue damage evaluation results of the three kinds of nozzle-like configuration models made of SUS304. Crack initiation test on the models has been conducted in Thermal Shock Test Sodium Loop to clarify crack initiation behavior in thermal bending stress conditions. The models have been loaded with two types of thermal bending stresses; one is caused by throughtout temperature distribution arisen in the nozzle-like configuration and the other is caused by temperature gradient arisen in the wall thickness of the models. Thermal transient test has been conducted under the condition that 550C and 300C sodium flow into the models for 5 hrs and 1 hr, respectively in one cycle, and finished after loading 1,700 cycles of thermal transient. After the test, crack inspection test by PT has been performed, and crack initiation at cross-sections interested have been observed successfully. For the analytical study, heat transfer analysis using the measured temperature data and inelastic thermal stress analysis were carried out by using cyclic stress-strain curves obtained from two kinds of strain rate conditions as the constitutive stress-strain relationships. Analysis results were utilized mainly for two objectives. One was to present the prospect of damage evaluation method based on inelastic analysis. And the other was to advance the present creep-fatigue damage evaluation method based on elastic analysis. Many analysis results and damage evaluation results of the test models are presented here, and discussed focusing on the application of inelastic analysis results to rational creep-fatigue failure predicting method.
; Umeda, Hisao; ; ;
PNC TN9410 92-116, 174 Pages, 1992/01
The design and fabrication of the Filletted vessel Thermal Bending Model which is to be tested at TTS are described in this report. The objective of this model is to obtain the thermal transient strength of biaxial stress condition, which appears at Y-piece structures or the portions in the vicinity of sodium surface, and fillet welding which are noteworthy portions from the structural integrity viewpoint of Fast Breeder Reactor (FBR) components. As the testing portion, this model has three kinds of skirt structure, a thick walled cylinder and four stabilizer plates which are attatched on inner shell by fillet welding. The objective of the skirt structures and the thick walled cylinder is to investigate the relations between stress ratio, hoop and axial stress, and thermal transient strength, and they are designed in order to have same maximum principal stress range and large variation in the ratio of hoop to axial stress. The model has a straw-bag-like body which constituted with filleted cylinders, a thick walled cylinder and upper/lower trisphere dished plate. The model is supported with support cone at lower trisphere dished plate. The model has inner shell which strive for sodium flow stability.
; ; ; *
PNC TN9410 91-295, 257 Pages, 1991/09
A failure test of a structure model was carried out under cyclic thermal transient stress in the thermal transient test facility for structures(TTS). After the test, destructive examination of the model clarified crackings as planned. Formerly inelastic analysis was applied to creep-fatigue damage evaluation, and good relationship was obtained between creep-fatigue damage and observed cracks. The result showed damage distributions were well corresponding to those of crack depth. The damage was not able to explain the crack propagation behavior, although could describe the crack initiation behavior. It was, therfore, important to assess the crack propagation behavior by fracture mechanics method in order to understand the crack propagation behavior. This report describes the crack analysis results of several cracks observed on the model named Thermal Stress Mitigation Structure Model (1). Axisy㎜etric finite element analyses were carried out for cyclic thermal transient loadings. It has been known that J-integral is path-dependent for thermal transient stress field. Therefore, J^ and J^' integrals for fatigue and creep crack growth, respectively were calculated by the CANIS-J code (Crack Analysis in Structure-J version). As the analysis results, J^ and J^' were almost path-independent, so these parameters were considered to be suitable for assessing the intensity of the crack-tip stress-strain field under thermal transient loadings. The distribution of J^ and J^' along the thickness direction were obtained. It was confirmed that J^ and J^' take the maximum values in nearly middle depth of the thickness and decrease gradually when crack depth exceed that point. Crack propagation behavior was simulated by such a manner that crack propagation rate was calculated from J^ and J^' integrals distributions with material crack growth law. The number of cycles of thermal transient, which was needed for cracks to propagate from the initial length (supposed to be 1mm) ...
*
PNC TN9410 90-135, 119 Pages, 1990/07
This study was carried out in order to examine the basic mechanical properties of the materials (SUSF304, SUS304TP and SUS304) which had the same specifications as was used for fabricating the Stress Mitigation Structure Model (1) Fatigue and creep tests were conducted and the results were compared with the best fit curve fatigue failure, creep strain equation and creep rupture equation of the material strength standard for "Monju". Besides, stress-strain curves at the steady state load cycle were compared with the standard bi-linear stress-strain relationship installed in FINAS, The results are surmmarized as follows. The materials had almost the same value for both fatigue failure strength and creep rupture strength as the average trend value of the material strength standard for "Monju". except for the creep rupture strength of the plate material which showed rather higher value. Besides, cyclic stress-strain curves and creep strain behavior showed nearly the same tendency as the standard or FINAS data. So, it should be said that inelastic thermal strees analysis and creep-fatigue damage evaluation can be done by usjng the average standard values described in the material strength standard for "Monju".
*
PNC TN9410 90-106, 349 Pages, 1990/06
This report describes the inelastic analysis and creep-fatigue damage evalution of the thermal Stress Mitigation Structure Model (1).The model was subjected to severe cyclic thermal transient loadings between 250C and 620C by using Thermal Transient Test Facility for Structures(TTS). Heat transfer analyses using the measured temperature data and both elastic and inelastic thermal stress analyses were carried out by using detailed structure models and cyclic stress-strain curves obtained from two kinds of strain rate conditions as the constitutive stress-strain relationship. As for analyses of weldments, metallurgically discontinuous modeling as well as homogeneous modeling were investigated. Analysis results were utilized mainly for two objectives. 0ne was to advance the present creep-fatigue damage evaluation method (TTSDS) based on elastic analysis results. And the other was to present the prospect of damage evaluation method based on inelastic analysis. Main discussions and results are summarized as follows. (1)Basically the shape of elastically evaluated creep-fatigue damage distributions along the structure surfaces were almost the same as the ones evaluated inelastically for almost all portions of the model except for geometrically discontinuous portions such as weldment edges. And both evaluations demonstrated a good agreement with the crack distribution on the structure surfaces. (2)But more precise analysis showed that creep-fatigue damage based on elastic analysis gave non-conservative value when strain concentration factor (K
in TTSDS) of 1.2 was uniformly assigned. Adequate value of K was evaluated up to 1.8 at certain weldment edges. (3)Bi-linear approximation of cyclic stress-strain curve at the condition of 1
10
l/s strain rate, corresponding to thermal transient test, gave larger strain range and larger creep-fatigue damage than the ones at the condition of 110
l/s ...
Tanaka, Nobuyuki; Watashi, Katsumi; Umeda, Hisao; Kikuchi, Masayuki; Iwata, Koji
Int Symp on Structral Mechanics in Reactor Technology, ,
None
Fukahori, Tokio; Shibata, Keiichi; Okumura, Keisuke; Iwamoto, Nobuyuki; Tanaka, Kenichi*
no journal, ,
The amount of radioactive wastes is estimated accurately and fundamental databases are needed to be produced emergently, so that disuse of nuclear plants is processed safely. In this presentation, as the first phase, methods of selection of target nuclides and production of activation cross sections, and studies on code libraries are reported.
Tanaka, Kenichi*; Fukahori, Tokio; Yamamoto, Masahiro; Sato, Tomonori; Motooka, Takafumi; Okumura, Keisuke; Shibata, Keiichi; Iwamoto, Nobuyuki
no journal, ,
The meaning and plan on development of standard and fundamental databases for material compositions and activation cross sections are introduced. Those database is important for estimation of radioactive nuclide production, which is necessary for safety management and waste estimation for disusing procedure of nuclear plants.
