Hitachi, Ltd.

The Tokyo Electric Power Company, Incorporated

Noriyuki Ohnaka

Masanori Sakai

Katsumi Ohsumi

Takuya Takahashi

Katsumi Mabuchi

Moriaki Fuyama

Yoshitaka Kojima

Yamato Asakura

Kenya Ohashi

Shigeo Hattori

Kiyoshi Miyake

Eiji Kikuchi

Makoto Hayashi

Yuichi Ishikawa

Kenichi Ito

Makoto Nagase

Masahisa Inagaki

Tadashi Iizuka

Motohiro Aizawa

Seishin Kirihara

Naohito Uetake

Masahiko Itoh

Shiro Kobayashi

Kazushi Fukuda

Hidefumi Ibe

Masakiyo Izumiya

Akira Mebata

Iwao Takase

Norio Watanabe

Yasuko Aoki

Masayoshi Kanno

Takashi Saito

Haruo Fujimori

Shizuka Yamaguchi

Yusaku Nakagawa

Hiroshi Yamauchi

Shoichi Nakashima

Masanori Takahashi

Sai Ogawa

Masayuki Doi

Kiyotomo Nakata

Yasuo Kamitsuma

Yukiyoshi Hara

Kazuhiko Akamine

Akihiko Chiba

Ryoichiro Ohoshima

Kouichi Yamane

Isao Ishi

Toshitaka Kida

Narutoshi Kazama

Takahashi Takuya

Yamauchi Hiroshi

Yusuke Isobe

Akira Ichimura

The composition of an alloy is inhomogeneous, so that the Fermi level of electrons in the surface of the alloy differs depending upon positions. It is accordingly considered that a part susceptible to corrosion and a part less susceptible thereto will coexist in the alloy. The corrosion rate of the alloy is indicated as the exponential function of a potential difference (.DELTA..PHI..sub.H) within an electric double layer. The potential difference remains unchanged as long as the Fermi level lies within the forbidden band of the electrons. However, in a range in which the Fermi level falls within the valence band of the electrons, the lowering thereof leads to the increase of the potential difference. Accordingly, a corrosion-resisting alloy is designed in accordance with the following guidelines: a) The electron energy level (Ev) of the valence band is low, b) an oxide film to be formed on the alloy is an n-type semiconductor, c) a band gap (Ec-Ev) is wide where Ec denotes the conduction band of the electrons, and d) a flatband potential (E.sub.f1) is low. Further, the operation of a plant and the evaluation of a corrosional damage can be based on such a theory.

Method of evaluating corrosion resistance of metal material, method of

A reactor water clean-up system is provided with a first filter demineralizer having a filter resin containing an alkali substance and a second filter demineralizer with a filter resin not containing an alkali substance. The reactor water is supplied to the first filter demineralizer during the term from the starting operation of the preoperating test of the nuclear reactor and of each fuel cycle to 2000 EFPH. The alkali substance contained in the filter resin is guided into the nuclear reactor to change the pH of the reactor water in the nuclear reactor to the weak alkali side. The Cr quantity which is taken in the oxide film of the fuel cladding tube surface is reduced. After 2000 EFPH from the starting operation, the supply of the reactor water to the first filter demineralizer is stopped, and then, the reactor water is supplied to the second filter demineralizer.

Boiling water reactor and its operating method

A highly corrosive-resistant metal having a high purity and a specific plane index is manufactured by ion beam deposition (IBD). A thin film having less defects and impurities is obtained. A magnetoresistant effect film for a magnetoresistant effect type magnetic head which is highly corrosion-resistant and exhibits excellent characteristics can be formed. In IBD according to the present invention, metal ions are provided with adjusted ion energy of 10 to 100 eV, and a metal having a particular mass number is selected by a mass separation electromagnet.

Magnetic disk device having a corrosion resistant magnetoresistive head

A system for monitoring the operation of a plant, which includes the facility of simulating the corrosion potential of a material and which can assess the effect of a countermeasure for mitigating the corrosion environment of the material, with the corrosion potential obtained by the simulation. The corrosion potential of the structural material of the plant is computed through a numerical analysis by applying an electrochemical mixed-potential theorem on the basis of the analytical result of a charge transfer reaction. Programs for such potential computations are prestored in a computer system from which data are accepted into a host computer. The computed corrosion potential is related with water quality data (for example, the concentration of hydrogen injected into the plant), and the relationship is output to a display unit.

Method of measuring a corrosion potential, method of simulating

A corrosion degree measuring method capable of field measurement for intergranular corrosion, particularly the sensitization degree, of the plant's structural materials in a narrow space. The metal electrode made of a material being measured and the counter electrode to the metal electrode are immersed in an electrolytic solution. A voltage is applied to the metal electrode in the anodic direction so as to raise the potential of the metal electrode up to the passive state potential and to keep the metal electrode at the passive state potential. The passive state potential is used as a reference potential, and a pulse-like potential signal is applied to the metal electrode in the cathodic direction. At the time of the application of the pulse potential signal, a current between the metal electrode and the counter electrode is measured, and the corrosion degree of the material being measured is determined from the intensity of the current.

Method and apparatus for measuring degree of corrosion of metal materials

Corrosion-resistant laminate which consists of a metal of a single mass

A water chemistry factor which is specific to a specific portion of a primary cooling system and universal is decided to be a standard target. The concentration of an agent for mitigating corrosion damage of structural material of the primary cooling system is controlled so that the target will be in a desirable range. All sensor groups provided in the primary cooling system are separated into sensor groups in different lines, of which a specific sensor group are connected to an arithmetic unit and a data base and are for always monitoring a plant process. For example, concentration distribution agreed with measured value oxidation component in the reactor water at the measurement points is selected from the data base, and it is used to estimate the standard target.

Nuclear power plant having a water chemistry control system for a

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.

Method and apparatus for measuring sensitization of structural members

The disclosure is concerned with a thermal land machine which comprises a heat resistant wall for confining a chamber; a heat resistant composite structure disposed in the chamber and in contact with a hot flowing gas; and an apparatus for introducing the hot gas toward the surface of the composite structure. The composite structure including a heat resistant substrate and a continuous refractory coating formed on the substrate and made of a ceramic material. The refractory coating includes at least two layers in a laminated structure each having fine cracks substantially extended in the direction of the thickness of each of the layers and filled with a refractory material in such a manner that the filled cracks in one layer are disconnected with the filled cracks in the adjacent layer. Therefore, the hot gas cannot permeate into the surface of the substrate.

Machine on ground provided with heat resistant wall used for isolating

A zirconium based alloy plate of low irradiation growth, containing not more than 5 wt % Sn and/or not more 5 wt % Nb, and the balance Zr of not less than 90 wt %. The alloy plate has a texture that &lt;0001&gt; orientation (Fr value) with respect to direction perpendicular to the surface of the plate ranges from 0.20 to 0.50. This alloy plate is effective in being used to form a fuel channel box. Also a fuel assembly using this channel box is provided in which the crystal orientation of the zirconium alloy is made random by a heat treatment. Specifically, by the heat treatment, the Fr, Ft, and Fl values thereof are set to 0.25 to 0.50, 0.25 to 0.36, and 0.25 to 0.36, respectively.

Zirconium based alloy plate of low irradiation growth, method of

A lead frame of a plastic encapsulated type semiconductor device is provided with a coating film which has a solderability higher than a solderability of a basic metal of the lead frame, and the coating film has a corrosion potential higher than a corrosion potential of the basic metal. The coating film protects the basic metal from corrosion caused by the plastic encapsulated member. The coating film of the lead frame made of a Fe-Ni alloy is an alloy comprising metal selected from Mo, W, Au, Cr, Cu, metals of the platinum group and a metal selected from Fe, Co, and Ni.

Lead frame for semiconductor device

A gas turbine bucket and a gas turbine nozzle applied with a ceramic coating comprises a base material of the bucket and the nozzle made of a heat resisting alloy; a plurality of coating layers for the front portion consisting of, a mixture layer which comprises a ceramic material and metal and which is formed on the base material, an alloy layer which comprises an alloy material exhibiting excellent resistance to high temperature oxidation and corrosion and which is formed on the mixture layer, and a ceramic layer which comprises ceramic material and formed on the alloy layer. Such ceramic coating has a satisfactory thermal barrier effect on the base material of the gas turbine bucket and nozzle.

Ceramics-coated heat resisting alloy member

This invention comprises electrochemical analytical devices capable of performing electrolysis in multiple pulse modes. It relates to a method of quantitative analysis and equipment for performing quantitative analysis which uses a combination of these pulse modes to realize the measurement of concentrations of multiple substances to be measured, occurring in the test solution to be measured and also a nuclear reactor water quality control system employing such a quantitative analysis method.

Solution quantitative analysis apparatus, quantitative analysis methods,

A sliding structure such as a compressor and etc. comprising a member made of an iron base material and another member having a porous ceramic layer slidably contacted with the iron base member, wherein the surface portion of the iron base member has both a porous oxide film containing tri-iron tetroxide as a main constituent, and an oxynitride layer formed under the oxide film.

Sliding structure such as compressor or the like

This invention comprises electrochemical analytical devices capable of performing electrolysis in multiple pulse modes. It relates to a method of quantitative analysis and equipment for performing quantitative analysis which uses a combinaiton of these pulse modes to realize the measurement of concentrations of multiple substances to be measured, occurring in the test solution to be measured and also a nuclear reactor water quality control system employing such a quantitative analysis method.

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Katsuta, Japan

Noriyuki Ohnaka