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Teshigawara, Makoto; Harada, Masahide; Saito, Shigeru; Kikuchi, Kenji; Kogawa, Hiroyuki; Ikeda, Yujiro; Kawai, Masayoshi*; Kurishita, Hiroaki*; Konashi, Kenji*
Journal of Nuclear Materials, 343(1-3), p.154 - 162, 2005/08
Times Cited Count：10 Percentile：56.74(Materials Science, Multidisciplinary)For decoupled and poisoned moderator, a thermal neutron absorber, i.e., decoupler, is located around the moderator to give neutron beam with a short decay time. A B4C decoupler is already utilized, however, it is difficult to use in a MW class source because of He void swelling and local heating by (n,a) reaction. Therefore, a Ag-In-Cd (AIC) alloy which gives energy-dependence of macroscopic neutron cross section like that of B
C was chosen. However, from heat removal and corrosion protection points of view, AIC is needed to bond between an Al alloy (A6061-T6), which is the structural material of a moderator. An AIC plate is divided into a Ag-In (15wt%) and Ag-Cd (35wt%) plate to extend the life time, shorten by burn up of Cd. We performed bonding tests by HIP (Hot Isostatic Pressing). We found out that a better HIP condition was holding at 803 K, 100 MPa for 1 h for small test pieces (f20mm). Though a hardened layer is found in the bonding layer, the rupture strength of the bonding layer is more than 20 MPa, which is less than that of the design stress.
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 B
C 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 (
20
2mm) 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 500
C 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.
Harada, Masahide; Teshigawara, Makoto; Kai, Tetsuya; Sakata, Hideaki*; Watanabe, Noboru; Ikeda, Yujiro
JAERI-Research 2001-016, 32 Pages, 2001/03
JAERI-Research-2001-016.pdf:1.74MB
An optimization study on the premoderator, the reflector material choice and a length of the liner is carried out for the design of high performance decoupled hydrogen moderator. NMTC/JAM and MCNP-4C are used for the neutronics calculation. The result indicates that, assuming premoderator dimensions and decoupling energy is controlled, the decoupled hydrogen moderator with a premoderator can provide better pulse characteristics than that without the premoderator for a Be reflector. On the selection of the reflector material, it is clearly shown that Pb and Hg reflectors give merits in using the premoderator for higher intensity and reduction of energy deposition in moderator. It is also shown that a H2O premoderator provides a short tail while a D2O premoderator provides the high peak intensity. Minimum liner length is evaluated to be 20 cm from the viewpoint of neutronics.
Maruyama, Yu; Sugimoto, Jun
Journal of Nuclear Science and Technology, 36(10), p.914 - 922, 1999/10
Times Cited Count：3 Percentile：28.69(Nuclear Science & Technology)no abstracts in English
Yanagisawa, Kazuaki; ; Horiki, Oichiro; D.Chen*; *
JAERI-M 91-211, 93 Pages, 1992/01
no abstracts in English
Kishimoto, Yasuaki; *
JAERI-M 89-061, 59 Pages, 1989/05
no abstracts in English
Nagase, Fumihisa; Uchida, Masaaki
JAERI-M 88-058, 26 Pages, 1988/03
no abstracts in English
; ; ; ;
JAERI-M 83-087, 16 Pages, 1983/06
no abstracts in English
; Ikawa, Katsuichi; Iwamoto, K.
Journal of Nuclear Materials, 80(1), p.184 - 186, 1979/00
Times Cited Count：1no abstracts in English
; ; Takeda, Tatsuoki
Nuclear Fusion, 13(1), p.119 - 120, 1973/01
Times Cited Count：12no abstracts in English
Sakai, Akihiro
no journal, ,
Japan Atomic Energy Agency (JAEA) is promoting the project for near surface disposal of low-level radioactive waste generated from research facilities, etc. Since a function to reduce infiltration water into the cover soil is needed at trench facilities for very low-level waste, we are calculating the infiltration water through the cover soil which is installed in various composition and parameters of the impermeable sheet, low permeable soil layer and drainage layer by using the HELP code developed by EPA and a calculation code by two-dimensional finite element method. This report outlines these studies that have been conducted on the impermeable function of the trenching facilities.
