Abstract: 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.

Abstract: 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%.

Abstract: A method and system for electrochemically measuring the sensitization to stress corrosion cracking of small pipes of plant structural members in a very short period of time. A micro electrochemical cell for measuring the sensitization is movably disposed within a BWR plant ICM housing or an instrumentation pipe. An electrochemical instrumentation system for performing the electrochemical potential variation such as pulse voltammetry and a remote control system for remotely controlling the electrochemical cell are provided.

Abstract: A plant operational status monitoring supervisory system comprising; means for extracting information directly relating to water quality of an objective portion consecutively for a period of time by means of an electrochemical water quality sensor installed in an objective portion to monitor in-situ in a plant; means for evaluating water quality based on thus extracted information; means for comparing an obtained water quality evaluation result with a reference value for a predetermined plant operation procedure; and means for displaying or storing necessary portion out of said comparison results; is disclosed.

Abstract: An austenitic steel comprising Ni of 9-30%, Cr of 10-23%, and Fe of at least 45%, is characterized in comprising enough Cr and Ni to form whole austenitic structure in the equilibrium diagram at 700.degree. C., having austenitic phase at room temperature, and the austenitic phase is a single crystal, and has superior resistance against stress. The austenitic steel preferably comprises C.ltoreq.0.1%, Si.ltoreq.1%, Mn.ltoreq.2%, Ni 9-15%, Cr 16-18.5%, and at least one of elements selected from the group of Mo 1-3%, Ti 0.05-1%, and Nb 0.1-1.5%. The alloy is useful as a material for members of a reactor core of a nuclear reactor.

Abstract: A method of descaling stainless steel which provides a smooth and glossy surface, comprises the steps of (a) anode-electrolyzing stainless steel having scales thereon in an aqueous neutral salt solution, (b) anode-electrolyzing or immersing the stainless steel in an aqueous alkaline solution. Steps (a) and (b) are performed in the order of either (a), (b), (a). The method further comprises the step of cathode-electrolyzing the stainless steel treated in the previous two steps in an aqueous nitric acid solution or immersing it in an aqueous solution of a mixture containing nitric acid and fluoric acid.

Abstract: A semiconductor module comprises semiconductor elements, cooling structures for cooling the semiconductor elements by liquid refrigerant, and a housing for accommodating the semiconductor elements and the cooling structures, wherein within the housing, there is supplied or enclosed sealingly a reactive gas which reacts with ions of a metal constituting the cooling structures to form a chemical compound hard to dissolve to the refrigerant but does not react with the metal itself constituting the cooling structures.

Abstract: A nuclear power plant using a structural material consisting of metal which comes into contact with a liquid in which radioactive substances are dissolved has a function to suppress the deposition of the radioactive substances. In this function, metal elements constituting the surface layer of the structural material which comes into contact with the liquid are oxidized by injecting oxidizing agents from outside, thereby preliminarily producing an oxide film. The oxidizing agents comprise at least one kind selected from the group consisting of oxygen, hydrogen peroxide, chromate, nitrite, molybdate, tungstate and ferrate. Particularly, by suppressing the deposition of radioactive substances on a stainless steel, the dose rate of exposure of workers is effectively reduced.

Abstract: A method of inhibiting corrosion of carbon steel piping of condensate and feed water systems in a power generating plant, characterized by continuing the water in said piping to flow after also said plant has been shut down until it is restarted up and by keeping the specific electric conductivity of flowing water at 0.5 .mu.S/cm or less.

Abstract: A novel low C-Cr-Mo steel having an excellent weldability and a high erosion-corrosion resistance under wet steam, which consists of, in % by weight, 0.02-0.14% of C, not more than 0.90% of Si, 0.30-0.80% of Mn, 0.70-1.60% of Cr, 0.40-0.70% of Mo and the remainder being substantially Fe. This novel steel is a very excellent material for fabricating the portions in the feed-water heater, for example, for a nuclear power generation plant, the portions being used under wet steam condition. The above described weldability and erosion-corrosion resistance can be improved by additionally adding the second components of Cu, N, or B, the third components of Nb or V or the fourth components of Al, Ti or Zr in the respectively defined amounts.

Abstract: A horizontal feedwater heater for use in heat power stations, of the type having a shell, a plurality of U-bent heat transfer tubes extended in the longitudinal direction of the shell and a vent tube extended in the longitudinal direction of the shell substantially at the center of the latter and adapted for extracting and discharging non-condensed gas. The feedwater heater has a baffle disposed at each side of the vent tube and having a horizontal plate portion extended horizontally from the vent tube and an inclined plate portion inclined downwardly from the end of the horizontal plate portion at an obtuse angle to the latter.

Abstract: A novel low C-Cr-Mo steel having an excellent weldability and a high erosion-corrosion resistance under wet steam, which consists of, in % by weight, 0.02-0.14% of C, not more than 0.90% of Si, 0.30-0.80% of Mn, 0.70-1.60% of Cr, 0.40-0.70% of Mo and the remainder being susbtantially Fe. This novel steel is a very excellent material for fabricating the portions in the feed-water heater, for example, for a nuclear power generation plant, the portions being used under wet steam condition. The above described weldability and erosion-corrosion resistance can be improved, by additionally adding the second components of Cu, N, or B, the third components of Nb or V or the fourth components of Al, Ti or Zr in the respectively defined amounts.