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[1994_01]
Journal of Nuclear Materials, 210 (1994) 233-238
Kan Ashidaa, Masao Matsuyamaa, Kuniaki
Watanabea, Hiroshi Kawamurab, Etsuo Ishitsukab
a Hydrogen Isotope Research Center, Toyama University, Gofuku 3190, Toyama 930, Japan
b Japan Atomic Energy Research Institute,
Oarai Research Establishment, Oarai-Machi, Higashi Ibaraki-gun, Ibaraki 311-13, Japan
Absrtract
With respect to the impurity emission and erosion of a Be first wall, a secondary ion mass spectrometric investigation was carried out along with surface characterization with X-ray photoelectron spectroscopy. It was found that Be is emitted as distinct types of chemical from the surface owing to sputtering with Ar+ and an (Ar+ + D+2) mixture: (i) Be and Be-cluster, (ii) oxide and hydroxide, and (iii) hydride and/or deuteride.
[1994_02]
Appl. Radiat. Isot., 45(3) (1994), 301-307
TOYOSABURO TAKEUCHI1, ATSUO MORI2,
MASAO MATSUYAMA1 and OSAMU TAKAYASU2
1 Hydrogen Isotope Research Center, Toyama University, Toyama 930, Japan
2 Faculty of Science, Toyama University, Toyama 930, Japan
Abstract
The separation of tritium from tritiated water (3.8 and 380 MBq/mol)
was studied by leaching of various Raney alloys, Al-Ni, Al-Co, Al-Cu (1:1),
and powdered Al, with NaOH solution of tritiated water. Diluted T-hydrogen
gas, about 1/10 of the original tritiated water, was released by the leaching.
Remarkably enriched T-hydrogen (about 100 times the level of the original
T-water) was released when the leached alloy-residue was heated to >300
°C. The stoichiometrical deficiency of Al in Raney alloy to NaOH expressed
by the following equation increased the efficiency of the enrichment. Al
+ NaOH + H2O uml; NaAlO2
+ 3/2H2. Powdered Al gave dilute T-hydrogen but no enriched
T-hydrogen from the residue, though the temperature was elevated to 100
°C.
The results showed that the leaching reaction
of Raney alloys is available for the enrichment and recovery of tritium
from tritiated water. Two reaction mechanisms for the enrichment are proposed.
[1994_03] *This paper is written in Japanese.
J. of Plasma and Fusion Research, 70(1) (1994) 36-44
K. Watanabe, M. Matsuyama
Hydrogen Isotope Research Center, Toyama University, Toyama 930, Japan
Abstract
This paper briefly reviews the recent development on the measurement of high concentration tritium required for thermonuclear fusion devices such as small ionization chamber, bremsstrahlung counting and fluorescent counting methods. The former two are promising for in-situ measurement of tritium in the range from 1x10-6 to 2.7 Ci/cm3 (=1 atmospheric pressure). The last one is excellent for a higher concentration range. As for the gas analysis, infrared absorption and laser Raman spectroscopies are revealed to be excellent for gas analysis up to one atmospheric pressure. Problems to be solved in near future are also discussed.
[1994_04]
Proc. of the 2nd Japan/China Symposium on Materials for Advanced New Energy Sys. and Fission and Fusion Engn., p.187-193, June 5-8, (1994), The Univ. of Tokyo, Tokyo, Japan
Kuniaki Watanabe, Masao Matsuyama, Toshinari Yamazaki
*Hydrogen Isotope Research Center, Faculty of Engineering, Toyama University, Gofuku 3190, Toyama 930, Japan
Abstract
Accuracy and reliability of a small ionization chamber
and a bremsstrahlung X-ray counter have been examined by using three kinds
of tritium gases. The ratio of tritium concentration in T2-gas
to that in HT-gas measured by bremsstrahlung counting method agreed quite
well with the concentration ratio determined from mass spectrometer. On
the other hand, the ration between DT- and HT-gases was about 10% higher
by the ionization chamber as well as the bremsstrahlung counting method
than that evaluated with the mass spectrometer. This discrepancy could
be understood to be due to hydrogen contamination of the DT-gas and rather
poor resolution of the mass spectrometer used.
Keywords: high concentration tritium, small ionization
chamber, bremsstrahlung X-ray counter, mass spectrometer, D-T fuel processing
[1994_05]
J. ENVIRON. SCI. HEALTH, A29(2) (1994) 281-299
Kiyoshi Hasegawa, Hiroshi Fusumae, Shoichi Miyahara and Manabu Shinohara
Chemical and Biochemical Engineering, Faculty of Engineering, Toyama University, Gofuku 3190, Toyama 930, Japan
Masao Matsuyama and Kuniaki Watanabe
Hydrogen Isotope Research Center, Toyama University, Gofuku 3190, Toyama 930, Japan
Abstract
The effects of air pollutants on UV-stimulated
HT oxidation were studied by selecting CCl4 as a model pollutant.
Mixture gases consisting of H2 + HT, O2 and CCl4
were irradiated with a high pressure mercury lamp. The reaction products
were found to be HTO and TCl. The role of CCl4 was evaluated
by measuring the formation rate of HTO + TCl as a function of the partial
pressure of CCl4. The reaction took place in two stages. During
the first stage, the extent of the reaction increased almost linearly with
time. During the second stage, the rate became faster with time, showing
a similar feature to autocatalytic reactions. It was found that those rates
were considerably increased with the pressure of CCl4. In the
case of 1.0 Torr, the rate of the first stage was 60 times greater than
that of the UV-stimulated HT oxidation previously reported, and that of
the second stage was about 10 times that of the first stage. As a whole,
the CCl4-assisted UV-stimulated HT oxidation showed a 5 ×
104 -5 ×105 times greater reaction rate than
the β ray-induced radiochemical HT oxidation.
With the aid of computer simulation including 47 relevant elementary
reactions, the enhanced acceleration of the reaction was understood as
a result of the formation of new reaction paths such as Cl --> H -->
HO2--> H2O and Cl --> H --> HO2--> OH --> H2O, which lacked in the UV-stimulated HT oxidation mechanism.
Keywords: tritium, oxidation, tritiated water,
UV-irradiation, carbon tetrachloride, acceleration effect, autocatalytic
effect
[1994_06] *This paper is written in Japanese.
[1994_07]
Proc. of the 2nd Japan/China Symposium on Materials for Advanced New Energy Sys. and Fission and Fusion Engn., p.136-142, June 5-8, (1994), The Univ. of Tokyo, Tokyo, Japan
K. Watanabe
Hydrogen Isotope Research Center, Toyama University, Gofuku 3190, Japan
Abstract
The study of tritium-material interaction is a key
for the safe handling of a large amount of tritium in thermonuclear fusion
reactors. Tritium data are vital to understand the nature of tritium-material
interaction and to predict tritium behavior in reactor systems. Studies
of isotope effects are also required to utilize hydrogen/deutrium data.
Another importance of tritium study is to make clear radiological phenomena:
namely, emission of b-rays and x-rays, production
of 3He and their effects. The present paper reviews the recent status of
tritium-material interaction studies in Japan.
Keyword: tritium, material interaction, Japanese
activity, isotope effect, b-rays, X-rays, helium