Pitting damage in metals by mercury cavitation with MIMTM

Yoshiie, Toshimasa*; Futakawa, Masatoshi; Naoe, Takashi; Komatsu, Masao*; Sato, Koichi*; Xu, Q.*; Kawai, Masayoshi*

Materia, 52(8), p.390 - 394, 2013/08

https://doi.org/10.2320/materia.52.390

In the liquid mercury target for the spallation neutron source, pressure waves occurs owing to the high-intense proton beam bombardment. The pressure waves induces the cavitation in the interface between the mercury and the target vessel through the propagation process. Erosion damage composed of micro-pits clusters is formed by the micro-jets and shock waves emitted from cavitation bubble collapse. In this paper, researches for damage structure of the material that was examined using the electroMagnetic IMpact Testing Machine (MIMTM) form the viewpoint of high-speed deformation. The result showed that the 200300 m/s of collision velocity for micro-jet impacting which was estimated from the numerical simulation is reasonable value.

Measurements of time-dependent stress distribution on material after HP impact

Kawai, Masayoshi*; Futakawa, Masatoshi; Naoe, Takashi; Xu, C.-N.*; Yamada, Hiroshi*

Proceedings of 7th International Symposium on Impact Engineering (ISIE 2010) (CD-ROM), p.380 - 385, 2010/07

We have proposed a sophisticated novel method of the SHB experiment to measure the time-dependent local strain distributions on a surface of the specimen by using mechanoluminescent materials combined with a high-speed camera and an image intensifier. The feasibility study was made for the aluminum specimens pasted with a typical mechanoluminescent material -Eu doped SrAlO film, in order to obtain the fundamental data for the method. Our results showed that SrAlO: Eu emitted lights as a response to the strain. Rise up of the light intensity was swift enough to follow the strain change due to HP impact. The luminescence intensity was experimentally verified and expressed as product of strain and strain rate. Accordingly, it can be said that this method gives a good tool for measuring time variation of local strain distributions.

Mechanical properties of austenitic stainless steels irradiated at SINQ target 4

Saito, Shigeru; Hamaguchi, Dai; Usami, Koji; Endo, Shinya; Ono, Katsuto; Matsui, Hiroki; Kikuchi, Kenji*; Kawai, Masayoshi*; Yong, D.*

Proceedings of 1st International Workshop on Technology and Components of Accelerator-driven Systems (TCADS-1) (Internet), 9 Pages, 2010/03

The research and development for an accelerator-driven system (ADS) to transmute minor actinide (MA) have been progressed. The target beam window of ADS submerged in the reactor will be subjected to high-energy proton and spallation neutron irradiation. To evaluate mechanical properties of irradiated materials, post irradiation examination (PIE) of the STIP (SINQ target irradiation program) specimens was carried out at JAEA. In the present study, PIE on austenitic steels JPCA and Alloy800H irradiated at SINQ target 4 (STIP-II) was conducted. Austenitic steels are preferable as the material for the target beam window of ADS from the view point of DBTT shift, which should be taken into consideration for ferritic / martensitic steels. The irradiation conditions were as follows: proton energy was 580 MeV, irradiation temperatures were ranged from 100 to 450C, and displacement damage levels were ranged from 6.5 to 19.5 dpa. Tensile tests were performed in air at R.T. to 350C. Results of the tensile tests performed at R.T. indicate that irradiation hardening occurred with increasing displacement damage level up to 10 dpa. At higher doses, irradiation hardening seemed to tend to saturate. Degradation of ductility was bottomed around 10 dpa and specimens kept its ductility until 19.5 dpa. All the specimens fractured in ductile manner.

Reaction kinetics analysis of damage evolution in accelerator driven system beam windows

Yoshiie, Toshimasa*; Xu, Q.*; Sato, Koichi*; Kikuchi, Kenji; Kawai, Masayoshi*

Journal of Nuclear Materials, 377(1), p.132 - 135, 2008/06

https://doi.org/10.1016/j.jnucmat.2008.02.059

Reaction kinetic analysis was used to estimate the damage evolution in window materials of 800 MWth ADS. Parameters were fitted to F82H of the STIP-II experiment and EC316LN of the STIP-I experiment. In F82H, the concentration of bubbles was almost constant and the bubble size increased, while the concentration of interstitial type dislocation loops increased and their size was constant between 310 and 300 dpa. EC316LN showed almost the same behavior. Swelling increased almost linearly with irradiation dose above 3 dpa between 673 K and 773 K.

Development of aluminum (Al5083)-clad ternary Ag-In-Cd alloy for JSNS decoupled moderator

Teshigawara, Makoto; Harada, Masahide; Saito, Shigeru; Oikawa, Kenichi; Maekawa, Fujio; Futakawa, Masatoshi; Kikuchi, Kenji; Kato, Takashi; Ikeda, Yujiro; Naoe, Takashi*; et al.

Journal of Nuclear Materials, 356(1-3), p.300 - 307, 2006/09

https://doi.org/10.1016/j.jnucmat.2006.05.017

We adopted silver-indium-cadmium (Ag-In-Cd) alloy as a material of decoupler for decoupled moderator in JSNS. However, from the heat removal and corrosion protection points of view, the Ag-In-Cd alloy is needed to clad between Al alloys (Al5083). We attempted to obtain good bonding conditions for between Al5083 and ternary Ag-In-Cd alloys by HIPing tests. The good HIP condition was found for small test piece (20mm). Though a hardened layer due to the formation of AlAg was found in the bonding layer, the rupture strength of the bonding layer was more than 20 MPa, which was the calculated design stress. Bonding tests of a large size piece (20020030 mm), which simulated the real scale, were also performed according to the results of small size tests. The result also gave good bonding and enough required-mechanical-strength, however the rupture strength of the large size test was smaller than that of small one.

Tensile properties of austenitic stainless steels irradiated at SINQ target 3

Saito, Shigeru; Kikuchi, Kenji; Usami, Koji; Ishikawa, Akiyoshi; Nishino, Yasuharu; Kawai, Masayoshi*; Dai, Y.*

Journal of Nuclear Materials, 343(1-3), p.253 - 261, 2005/08

https://doi.org/10.1016/j.jnucmat.2005.02.010

A beam window of a spallation target will be subjected to proton/neutron irradiation, pressure wave and thermal stresses accompanied by high-energy proton beam injection. To obtain the irradiation data, the SINQ target irradiation program (STIP) was initiated in 1996 at Paul Scherrer Institute (PSI) and has been progressing. JAERI takes part in STIP and shares the PIE work. In this study, the results of tensile tests on austenitic stainless steels, JPCA and 316F SS, will be reported. The results indicate that the irradiation causes considerable hardening and degradation of ductility. The YS increases in this study are slightly large in comparison with those irradiated at fission reactor. Strain-to-necking (STN) values show sufficient large ductility of the irradiated JPCA-SA and 316F-SA. The trends of the STN decrease in this study are slightly abrupt in comparison with those irradiated at fission reactor. All specimens, including irradiated at embrittlement temperature for austenitic steels, fractured in ductile manner.

Review of neutron cross-section evaluations for fission products

Oblozinsk, P.*; Herman, M.*; Mughabghab, S. F.*; Sirakov, I.*; Chang, J.*; Nakagawa, Tsuneo; Shibata, Keiichi; Kawai, Masayoshi*; Ignatyuk, A. V.*; Pronyaev, V. G.*; et al.

AIP Conference Proceedings 769, p.438 - 441, 2005/05

https://doi.org/10.1063/1.1945042

Review of neutron cross-section evaluations for fission products included in 5 major evaluated nuclear-data libralies was performed. The aim of the project, conducted under the WPEC Subgroup 21 during 2001-2004, was to prepare recommendations for best evaluations of nuclei in the range Z=1-68. Altogether, existing evaluations for 211 materials were reviewd, 7 new materials were added, and recommendations were prepared for 218 materials.

Spallation terget materials development

Kikuchi, Kenji; Kawai, Masayoshi*; Ikeda, Yujiro

Proceedings of 6th International Meeting on Nuclear Applications of Accelerator Technology (AccApp '03) (CD-ROM), p.17 - 25, 2004/00

Spallation target being developed for high intensity neutron source of MW incident proton power. Mercury is a primary target material in pulsed spallation neutron sources, lead-bismuth is a candidate target material in the accelerator-driven system (ADS) for nuclear transmutation, and tungsten is a back-up solid target for pulsed spallation neutron sources and a candidate for ADS target. Current status of these project and materials issues are stated.

Evaluations of heavy nuclide data for JENDL-3.3

Kawano, Toshihiko*; Matsunobu, Hiroyuki*; Murata, Toru*; Zukeran, Atsushi*; Nakajima, Yutaka*; Kawai, Masayoshi*; Iwamoto, Osamu; Shibata, Keiichi; Nakagawa, Tsuneo; Osawa, Takaaki*; et al.

JAERI-Research 2003-026, 53 Pages, 2003/12

JAERI-Research-2003-026.pdf:2.48MB

New evaluations of neutron nuclear data for Uranium, Plutonium, and Thorium isotopes which are essential for applications to nuclear technology were carried out for the Japanese Evaluated Nuclear Data Library, JENDL-3.3. The objectives of the current release of JENDL were to fix several problems which have been reported for the previous version, to improve the accuracy of the data, and to evaluate covariances for the important nuclides. Quantities in JENDL-3.2 were extensively re-evaluated or replaced by more reliable values. The heavy nuclide data in JENDL-3.3 were validated with several benchmark tests, and it was reported that the current release gave a good prediction of criticalities.

Silver-indium-cadmium decoupler and liner

Harada, Masahide; Saito, Shigeru; Teshigawara, Makoto; Kawai, Masayoshi*; Kikuchi, Kenji; Watanabe, Noboru; Ikeda, Yujiro

Proceedings of ICANS-XVI, Volume 2, p.677 - 687, 2003/07

As a decoupler material for intense neutron sources, we proposed a new composite material based on the (n,) reaction, silver-indium-cadmium alloy (AIC), which had lettle helium gas production rate and higher decoupling energy (1eV). We compared an AIC decoupler with Cd and BC decouplers from various viewpoints and finally selected AIC as decoupler and liner materials. In the current design, we adopted AIC of 2.5mm thick with a composition of Ag-35wt%Cd and 0.5mm thick with Ag-15wt%In. A decoupler and a liner can be bonded to structural material (Al-alloy) by HIP for water cooling through Al-alloy. To find the optimal HIP condition, small pieces of Ag-Cd and Ag-In (202mm) were enclosed in Al-alloy capsules (22mm, 3mm thick bottom plate and 1mm thick cap) of several Al-alloys. The optimal condition was found to be 500C with a holding time of 60 minutes under a fixed pressure of 100MPa. Large pieces (Ag-Cd: 2002002.5mm, Ag-In: 2002000.5mm, A5083 and A6061: 21021021mm) were also tested aiming at more realistic size conditions.