二村　嘉明^*、佐川　尚司^**、島川　聡司^**、土谷　邦彦^**、黒田　敏公^***、河村　弘^**
*富山大学水素同位体機能研究センター
〒930　富山市五福3190
^**日本原子力研究所
〒311-13　茨城県東茨城郡大洗町成田町新堀3607
^***川崎重工業株式会社
〒136東京都江東区南砂2-4-25

Yoshiaki FUTAMURA^*, Hisashi SAGAWA^**, Satoshi SHIMAKAWA^**, Kunihiko TSUCHIYA^**, Toshimasa KURODA^***,Hiroshi KAWAMURA^**
*Hydrogen Isotope Research Center, Toyama University,Gofuku 3190, Toyama 930, JAPAN
^**Japan Atomic Energy Research Instirute,3607 Shinbori, Narita-cho, Higashi-ibaraki-gun, Ibaraki-ken, JAPAN
^***Kawasaki Heavy Industries, Ltd.,2-4-25 Minanisuna, Koutou-ku, Tokyo-to, JAPAN
(Received September 9, 1993; accepted November 7, 1993)

Abstract
To develop a tritium breeding blanket for a fusion reactor, irradiation tests in fission reactors are indispensable for obtaining data on irradiation effects on materials, and neutronics/thermal characteristics and tritium production/recovery performance of the blanket.
  Various irradiation tests have been conducted in the world, especially to investigate tritium release characteristics from tritium breeding and neutron multiplier materials, and materials integrity under irradiation.
  In Japan, VOM experiments at JRR-2 for ceramic breeders and experiments at JMTR for ceramic breeders and beryllium as a neutron multiplier have been performed. Several universities have also investigated ceramic breeders. In the EC, the EXOTIC experiments at HFR in the Netherlands and the SIBELIUS, the LILA, the LISA and the MOZART experiments for ceramic breeders have carried out. In Canada, NRU has been used for the CRITIC experiments. The TRIO experiments at ORR (ORNL), experiments at RTNS-Ⅱ, FUBR and ATR have been conducted in the USA. The last two are experiments with high neutron fluence aiming at investigating materials integrity under irradiation. The BEATRIX-Ⅰand -Ⅱ experiments have proceeded under international collaboration of Japan, Canada, the EC and the USA.
  This report shows the present status of these irradiation tests following a review of the blanket design in the ITER CDA (Conceptual Design Activity).

峰岸　知也
千葉工業大学
〒275　千葉県習志野市津田沼2丁目17番1号

Tomoya MINEGISHI
Chiba Institute of Technology,Tudanuma 2-17-1, Narashino 275, Chiba, JAPAN
(Received December 24, 1993; accepted November 7, 1993)

Abstract
Since about 1970, metal hydrides have been prosperously invested for hydrogen storage materials as alternatives to the fossil fuels. The hydrides can contain a large amount of hydrogen in a solid state and supply it as a gas state. Many kinds of alloy systems have been researched and developed for hydrogen storage. Then we can classify them into the following three systems; 1) Titanium alloy system, 2) Magnesium alloy system and 3) rare metal (mainly Lanthanum) alloy systems. Among there systems, the magnesium alloy system, in comparison with the other two alloy systems, generally has some advantages such as light mass, lower cost and good quality of absorption and disadvantages, such as higher working temperature.
  The present review deals with issues on the behaviors and phenomena , such as diffusion, chemical reaction and rate of process, relating to the hydrogen in magnesium and its hydrides.

松山　政夫、渡辺　国昭、諸住　正太郎、飯島　正幸^*
富山大学水素同位体機能研究センター
〒930　富山市五福3190
^*三菱マテリアル㈱車両軽量化推進室
〒100　東京都千代田区大手町1-5-1

Masao MATSUYAMA, Kuniaki WATANABE, Shotaro MOROZUMI, Masayuki IIJIMA^*
Hydrogen Isotope Research Center, Toyama University,Gofuku 3190, Toyama 930, JAPAN
^*Mitsubishi Materials Corp.,1-5-1 Ohtemachi, Chiyoda-ku, Tokyo 100, JAPAN
Gofuku 3190, Toyama 930
(Received August 31, 1993; accepted November 7. 1993)

Abstract
Mg-Ⅲa transition metal alloys were hydrogenated at 773K (500℃) under 570 torr of hydrogen. The Ⅲa transition metals used were Sc, Y, and Ho as a lanthanide element. The hydrogenated alloys were examined for absorption and desorption behavior of hydrogen, internally hydrided structure, identification of hydrides, changes in hardness of the alloys, and effects of additive elements, such as Ag, Al, Cd, Li, Pb, Sn, and Zn, on the internal hydriding of Mg-5Y alloy.
  Results obtained are as follows:

1. The Mg-alloys containing Ⅲa transition metals could absorb much more amounts of hydrogen than magnesium-itself and form hydrides of the metals in the matrix.
2. These hydrides were identified as ScH₂, YH₂, and HoH₂, respectively, and formed on the specific crystallographic planes in the magnesium matrix. They were so stable that they did not decompose by heat treatment in a vacuum at the hydrogenating temperature.
3. The Mg-Sc alloys were hardened by internal hydriding, while softening took place in the Mg-Y and Mg-Ho alloys by hydriding. This discrepancy might be attributed to the difference in compromise between the decrease of solid solution hardening and the increase of dispersion hardening by hydriding. However, because of dispersed stable hydrides, all the internally hydrided alloys were expected to have an appreciable strength at high temperatures.
4. Investigating the effect of each additive element added by 2-3 at% on the internal hydriding of Mg-5 mass% (1.5 at%) Y alloy, it was found that the hydriding was almost arrested by the addition of Ag, Al, Cd, Pb, and Sn, respectively, and arrested to a certain degree by the addition of Zn, while it was little affected by the addition of Li.

松山　政夫、荒井　寛幸^*、山崎　登志成^*、池田　長康^*、渡辺　国昭
富山大学水素同位体機能研究センター
^*富山大学工学部電子情報工学科
〒930　富山市五福3190

Masao MATSUYAMA, Hiroyuki ARAI^*, Toshinari YAMAZAKI^*,Nagayasu IKEDA^*, Kuniaki WATANABE
Hydrogen Isotope Research Center, Toyama University
^*Faculty of Engineering, Toyama University
Gofuku 3190, Toyama 930, JAPAN
(Received August 31, 1993; accepted November 7, 1993)

Abstract
Improvements of the bremsstrahlung counting method proposed for in-situ measurements of high level tritium were performed from the viewpoint of increase in sensitivity. The major point of the improvements was made in regard to window material which acts as a generator and extractor of the bremsstrahlung X-rays. It was expected from computer simulation that a thin beryllium foil would be the most favorable window material for the present purposes.
  On the basis of the simulation, characteristics of the 0.25 mm thick beryllium foil was experimentally investigated by using tritium gas diluted with deuterium gas. The bremsstrahlung counting rate was proportional to the concentration of tritium above 1x10^-5 Ci/cm³, and also sensitivity increased above 500 times in comparison with a case of former glass tube.
  On the other hand, it was seen that the counting rate was affected by the total pressure of the gas containing tritium. Namely, above about 50 Torr, the counting rate decreased gradually with the total pressure. Such behavior was interpreted in terms of the self absorption of β-rays in the gas phase. It was revealed that the change in the counting rate can be fully reproduced by a exponential function taking into account the self-absorption.

芦田　完、渡辺　国昭、沢田　英一、多々　静夫、池野　進
富山大学水素同位体機能研究センター
富山大学工学部物質工学科
富山大学地域共同研究センター
〒930　富山市五福3190

Kan ASHIDA, Kuniaki WATABANE, Eiichi SAWADA, Shizuo TADA, Susumu IKENO
Hydrogen Isotope Research Center, Toyama University
Material Sci. and Eng., Faculty of Engineering, Toyama University
Center of Cooperative Research, Toyama University
Gofuku 3190, Toyama 930, JAPAN
(Received August 31, 1993; accepted November 7, 1993)

Abstract
Because of the limited nature of elemental metals, most of the hydrogen storage materials are used as alloys. To apply hydrogen storage materials to tritium processing systems, it is indispensable to understand alloying effects on their properties such as storage, supply, recovery, separation and others to develop/design new materials. From this viewpoint, alloying effects on the ab/desorption, kinetics of deuterium for the Zr-Ni system was studied. It was revealed that the absorption of deuterium obeys first order kinetics with respect to the deuterium pressure, whereas, the desorption obeys second order kinetics with respect to the amount of deuterium absorption. In addition, alloying Zr with Ni caused an increase in the activation energy for absorption; on the contrary, the activation energies for desorption decreased. The heat of the deuterium solution and/or deuteride formation, evaluated through the proposed potential energy diagram, was found to decrease with increasing Ni content.

金坂　績、織田　和宏

富山大学理学部
〒930　富山市五福3190

Isao KANESAKA, Kazuhiro ODA
Faculty of Science, Toyama University,Gofuku 3190, Toyama 930, JAPAN
(Received July 31, 1993; accepted November 7, 1993)

Abstract
Infrared spectra of CaSO₄・0.5H₂O-T₂O system were observed for ca. 200 days. At one day after introducing T₂O, CaSO₄・2H₂O (T₂O) is formed, whose reaction dose not proceed in the H or D system. The infrared spectra changed little, except for a decrease in the intensity of ν₃ of sulfate ions and the appearance of a weak band at 750cm^-1 after 71 days. These changes were attributed partly to the decomposition of the sulfate ion and mainly to the formation of a new phase of dihydrate, which is stable in heat and T-βrays, and suitable for the removal of tritiated waters.

原　正憲^*、金坂　績^*、三宅　均^**、渡辺　国昭^**
*富山大学理学部
^**富山大学水素同位体機能研究センター
〒930　富山市五福3190

Masanori HARA^*, Isao KANASAKA^*, Hitoshi MIYAKE^**,Kuniaki WATANABE^**
*Faculty of Science, Toyama University
^**Hydrogen Isotope Research Center, Toyama University
Gofuku 3190, Toyama 930, JAPAN
(Received July 31, 1993; accepted November 7, 1993)

Abstract
An organic polymer is used as a conventional standard material for tritium beta-ray sources. It is, present study, cis-1, polybutadiene (CPB) was examined to be tritiated photochemically under UV irradiation. This method is expected to produce no tritiated byproduct, in contrast with conventional chemical syntheses from monomers having been applied to prepare standard tritium beta-ray sources and to immobilize tritium in the form of organic polymers.
  It was found that the UV irradiation on CPB in the presence of HT could cause CPB tritiated with producing no detectable tritiated byproduct. In addition, it was also observed that CPB was isomerized to its trans-isomer. There was a linear relation between the tritiation and the isomerization of CPB. A [－CH₂－CH=CH－CH－] radical mechanism was proposed for the tritiation and the isomerization. The extent of the tritiation was rather low in the present study as 432MBq/g for 10 hour UV irradiation from a low pressure mercury lamp (5W) at 30 Torr of HT. The specific activity, however, was comparable to conventional beta-ray sources and hence this method is promising to prepare standard tritium beta-ray sources without producing tritiated byproducts.
  The low tritiation yield appeared to be due to the fact that HT molecules do not react readily with the radicals. This method, however, could be improved for immobilization of waste tritium by making tritium radicals in suitable ways.