Quantitative analyses of impurity silicon-carbide (SiC) and high-purity-titanium by neutron activation analyses based on k standardization method; Development of irradiation silicon technology in productivity using research reactor (Joint research)

Motohashi, Jun; Takahashi, Hiroyuki; Magome, Hirokatsu; Sasajima, Fumio; Tokunaga, Okihiro*; Kawasaki, Kozo*; Onizawa, Koji*; Isshiki, Masahiko*

JAEA-Technology 2009-036, 50 Pages, 2009/07

JAEA-Technology-2009-036.pdf:32.66MB

JRR-3 and JRR-4 have been providing neutron-transmutation-doped silicon (NTD-Si) by using the silicon NTD process. We have been considering to introduce the neutron filter, which is made of high-purity-titanium, into uniform doping. Silicon carbide (SiC) semiconductors doped with NTD technology are considered suitable for high power devices with superior performances to conventional Si-based devices. The impurity contents in the high-purity-titanium and SiC were analyzed by neutron activation analyses (NAA) using k standardization method. Analyses showed that the number of impurity elements detected from the high-purity-titanium and SiC were 6 and 9, respectively. Among these impurity elements, Sc detected from the high-purity-titanium and Fe detected from SiC were comparatively long half life nuclides. From the viewpoint of exposure in handling them, we need to examine the impurity control of materials.

Steady state neutron source by reactor

Morii, Yukio; Isshiki, Masahiko

Kessho Kaiseki Handobukku, p.111 - 114, 1999/09

no abstracts in English

Status of reduced enrichment program for research reactors in Japan

Kanda, Keiji*; *; Isshiki, Masahiko; Baba, Osamu; Tsuruta, Harumichi

1996 Int. Meeting on Reduced Enrichment for Research and Test Reactors (RERTR), 0, 8 Pages, 1996/00

no abstracts in English

None

Morinaga, Masahiko*; Inoue, Satoshi*; Saito, Junichi*; *; *; Kano, Shigeki; Tachi, Yoshiaki

PNC TY9623 93-005, 134 Pages, 1993/03

PNC-TY9623-93-005.pdf:6.09MB

None

None

Morinaga, Masahiko*; Saito, Junichi*; *; *; *; Kano, Shigeki; Yoshida, Eiichi

PNC TY9623 92-001, 73 Pages, 1992/04

PNC-TY9623-92-001.pdf:6.17MB

None

Design of super-heat-resisting structural materials using a d-electron alloy theory (II)

*; Morinaga, Masahiko*; Saito, Junichi*; *; *

PNC TJ9623 92-001, 81 Pages, 1991/07

PNC-TJ9623-92-001.pdf:6.46MB

[PURPOSE] For structural materials serviced in the Li environments, both Nb-based and Mo-based alloys are selected as the candidate materials. In this study, a simple method was proposed for evaluating the high temperature strength of these alloys. Also, the corrosion resistance in liquid metals was investigated in order to get fundamental information for the design and development of high performance alloys. [EXPERIMENTAL AND CALCULATING METHODS] With a variety of ternary alloys high temperature micro-hardness was measured systematically. The results were analyzed by referring to the relationship between the hardness and the tensile strength reported in previous publications. Also, some alloys designed last year were exposed to the liquid Na at 650 C, and the attendant changes were examined with respect to the weight, microstructure and local composition of alloys. Some of the results were understood in terms of the free energy for the oxide formation of Na and other elements in alloys. Another effort to understand the corrosion properties was made by the molecular orbital calculation of the electronic states of various elements in liquid Li, K and Na. [RESULTS] The high temperature tensile strength of both the alloys was found to be predictable by using a linear relationship between the hardness and the tensile strength of room temperature to 1200 C. The corrosion resistance was much poorer in the Nb-based alloys than in the Mo-based alloys. This is partially due to the enhancement of corrosion by the preferred oxidation of Nb and Ta in the Nb-based alloys, whereas no such oxidation took place in the Mo-based alloys. In addition, it was found from the molecular orbital calculation that Li is the liquid metal of more strongly-bonded with every alloying element, compared to K and Na liquid metals. Futhermore, it was shown that the hardness of each alloy correlated well with the atomic-size difference and also the young's modulus difference ...

Reconstruction program for Japan Research Reactor-3

Onishi, Nobuaki; Isshiki, Masahiko; Takahashi, Hidetake;

Japan-China Symp. on Research and Test Reactors, 11 Pages, 1988/00

no abstracts in English

Shielding Analyses for Design of the Upgraded JRR-3 Research Reactor・2-Shielding of Neutron Beam Holes-

; ; ; ; ; *

JAERI-M 85-105, 113 Pages, 1985/07

JAERI-M-85-105.pdf:2.56MB

no abstracts in English

In-Situ Tritium Release Experiment of LiO(1)Planning and Safety Assesment

; Kurasawa, T.; ; ; Tanifuji, Takaaki; ; ; ; ;

JAERI-M 82-136, 27 Pages, 1982/10

JAERI-M-82-136.pdf:0.8MB

no abstracts in English

Thermal neutron flux distribution inside and outside LiO pellets

; *; Tanifuji, Takaaki; ; ; ; ;

Journal of Nuclear Materials, 88(2-3), p.193 - 198, 1980/00

https://doi.org/10.1016/0022-3115(80)90274-3

no abstracts in English