Hitachi, Ltd.

Shinzo Ikeda

Shigeru Azuhata

Hisao Yamashita

Shin Tamata

Shuichi Kanno

Toshiaki Arato

Kazuyoshi Irie

Ken Yasuda

Takahiko Kato

Yasuhisa Aono

Isao Masaoka

Masakiyo Izumiya

Kiyotomo Nakata

Akira Kato

Junjiro Nakajima

Takeshi Yasuda

Hideyo Kodama

Fumio Iida

Hiroshi Kawagoshi

Iwao Takase

Masayoshi Kanno

Toshimi Yoshida

Shigeki Kasahara

Shizuka Shimanuki

Heishichiro Takahashi

A gas stream containing at least one fluorine compound selected from the group consisting of compounds of carbon and fluorine, compounds of carbon, hydrogen and fluorine, compounds of sulfur and fluorine, compounds of nitrogen and fluorine and compounds of carbon, hydrogen, oxygen and fluorine is contacted with a catalyst comprising at least one of alumina, titania, zirconia and silica, preferably a catalyst comprising alumina and at least one of nickel oxide, zinc oxide and titania in the presence of steam, thereby hydrolyzing the fluorine compound at a relatively low temperature, e.g. 200&#xb0;&#x2013;800&#xb0; C., to convert the fluorine of the fluorine compound to hydrogen fluoride.

Process for treating fluorine compound-containing gas

A gas stream containing at least one fluorine compound selected from the group consisting of compounds of carbon and fluorine, compounds of carbon, hydrogen and fluorine, compounds of sulfur and fluorine, compounds of nitrogen and fluorine and compounds of carbon, hydrogen, oxygen and fluorine is contacted with a catalyst comprising at least one of alumina, titania, zirconia and silica, preferably a catalyst comprising alumina and at least one of nickel oxide, zinc oxide and titania in the presence of steam, thereby hydrolyzing the fluorine compound at a relatively low temperature, e.g. 200&#xb0;-800&#xb0; C., to convert the fluorine of the fluorine compound to hydrogen fluoride.

A method for treating a gas flow containing organohalogen compounds including the steps of contacting the gas flow with a catalyst at a temperature below 500.degree. C. in the presence of an effective amount of steam, wherein the catalyst contains titania, tungsten oxide, and silica, the Ti and W are present in the range of 20-95 mol % Ti and 5-80 mol % W based on Ti and W, and the amount of silica is in the range of 0.5-15% by weight silica to 100% by weight titania. Accordingly, the organohalogen compound can be decomposed effectively to carbon monoxide, carbon dioxide, and hydrogen halide.

Method for treating gas containing organohalogen compounds, and catalyst

A superconducting wire saved in weight and enhanced in mechanical properties is provided without damaging electric and thermal characteristics as an Al stabilizer, and further a method for producing the same, a high strength Al sintered alloy and powders used for the process are provided. A superconducting wire comprising an Al alloy of a high purity Al in which a small amount of ceramic ultrafine particles are dispersed and superconducting filaments embedded in the Al alloy, in which a large number of the ceramic ultrafine particles are dispersed in the area of 1 .mu.m.sup.2, and the areas of 1 .mu.m.sup.2 in which a large number of the ceramic ultrafine particles are dispersed, are formed over nearly the whole of the alloy.

Superconducting wire and composite superconductor

This invention provides austenitic steel having a superior resistance to neutron irradiation, a nuclear reactor and a nuclear fission reactor using such steel. In the present invention, austenitic steel containing at least one of Pd and Pt is used for a member which undergoes neutron irradiation in high-temperature water. More specifically, the steel consists essentially of not more than 0.02% C, not more than 1% Si, 0.5-15% Mn, 9-26% Cr, 8-20% Ni, 0.5-3% Mo, at least one kind of 0.1-16% selected from the group consisting of Pd and Pt, and not less than 50% Fe, and may further contain not more than 1.0% of at least one kind selected from the group consisting of Nb, Ti, Zr, Hf and V, and this is used for structural members in a core of a nuclear reactor and a nuclear fission reactor.

Structural member having superior resistance to neutron irradiation

A nuclear reactor having structural members made of austenitic stainless steel which is corrosion-resistant in an environment of neutron irradiation, and can suppress stress corrosion cracking and embrittlement. At least one additive selected from the group consisting of Ti more than 0.2% by weight but not more than 0.6%, Zr more than 0.2% but not more than 1.14%, Hf more than 0.2% but not more than 2.24%, V more than 0.2% but not more than 0.64%, Nb more than 0.5% but not more than 1.17% and Ta more than 0.5% but not more than 2.27% is added to austenitic stainless steel containing Cr, Ni and so on, and said at least one exists in a solid-solution state. In addition, the steel has a wholly austenitic structure substantially free of carbide. In order to maintain the irradiation-induced segregation prevention effected by the addition element, the C content is limited to 0.01 to 0.008%, and the N content is limited to 0.001 to 0.0%. The irradiation-induced segregation, of the constituent elements, such as Cr and Ni, occurring in a grain boundary under irradiation, can be prevented, and the deterioration of the corrosion resistance of the material, as well as the embrittlement, can be prevented.

A nuclear reactor comprising a reactor vessel and structural members

A method of producing cladding tube comprises a step of temperature-gradient annealing in which the inner surface of the tube is heated to a temperature higher than the recrystallization temperature thereof, while the outer surface of the tube is cooled, after the tube has been hot-extruded. The temperature-gradient annealing is effected while a temperature gradient is maintained between the inner surface and the outer surface of the cladding tube. While keeping the inner surface at a temperature higher than the recrystallization temperature, and the outer surface at a temperature lower than the recrystallization temperature. The cladding tube is obtained with the outer surface which has an excellent resistance to nodular corrosion and a soft inner surface which has an excellent resistance to stress corrosion cracking.

Method of producing a cladding tube for reactor fuel

Growing community of inventors

Naka-gun, Japan

Shinzo Ikeda