Hitachi, Ltd.

Hitachi-Ge Nuclear Energy, Ltd.

Masakazu Hisatsune

Satoru Aoike

Kenji Araki

Masatoshi Takada

Chikara Takeuchi

Masafumi Noujima

Kenji Utaka

Fuminobu Takahashi

Makiko Miyauchi

Satoshi Kanno

Yuuichirou Mizumachi

Koushi Sakata

Katsumasa Miyazaki

An method for converting tensile residual stress on an inner surface of a welded part of a pipe to compressive residual stress with use of ice plugs formed by cooling the pipe from the outer surface, comprises the steps of: placing refrigerant containers for forming the ice plugs in the upstream and downstream of a butt-welded part; cooling the outer surface of the pipe to form the ice plugs; and then cooling the outer surface of the pipe with use of at least one refrigerant container for expanding the pipe arranged between the refrigerant containers for forming the ice plugs. When the method is applied to a pipe with a large inside diameter, the method comprises forming the ice plugs at a curved pipe, an elbow or a branch pipe in the upstream and downstream of the butt-welded part.

Method for improving residual stress in pipe and apparatus

A wall-thickness thinning rate at a not-measured position is estimated using information having a small number of measured points. Simulation of behavior of fluid flowing inside a pipe line is performed based on wall-thickness data of pips and three-dimensional layout data of the pipe line including the pips using a computer, and simulated wall-thickness thinned data of the pipes composing the pipe line is calculated from change of the simulated behavior of fluid.

Method of offering wall-thickness thinning prediction information, and computer-readable recording medium storing wall-thickness thinning prediction program, and method of planning piping work plan

A wall-thickness thinning rate at a not-measured position is estimated using information having a small number of measured points. Simulation of behavior of fluid flowing inside a pipe line is performed based on wall-thickness data of pipes and three-dimensional layout data of the pipe line including the pipes using a computer, and simulated wall-thickness thinned data of the pipes composing the pipe line is calculated from change of the simulated behavior of fluid.

An image matching device for extracting differences between an image taken of an actual object and model data with high accuracy. The image matching device includes a model data storage unit for storing model data of a layout of component parts of a plant, an image data storage unit for storing, for example, data of images taken of the plant, a parts library containing data on parts, heat insulating material library containing information of heat insulating materials, a model correcting unit, and a matching unit. The model correcting unit produces, based on model data and parts data, synthesized image data of an image viewed from the same position and in the same direction as actual image data is obtained by taking a photo of the plant. The matching unit matches a synthesized image to a real image.

Image matching device

Nuclear fuels are taken from a nuclear reactor pressure vessel, a rail for running is mounted under the reactor pressure vessel drain piping in parallel with a horizontal portion of the reactor pressure vessel drain piping inside a pedestal positioned on the lower side of the reactor pressure vessel, an inspection apparatus is mounted on the-rail, and the inspection apparatus is moved along the rail to inspect the reactor pressure vessel drain piping, whereby the reactor pressure vessel drain piping can be surely inspected while reducing radiation exposure to an inspector.

Inspection method and apparatus for piping

In a thickness reducing management for pipes in pipe lines, limited proper parameters which cause erosion and corrosion of the pipes are selected and with these parameters a pipe thickness reducing speed evaluation model formulas are constructed, and by making use of the model formulas thickness reducing amount of the pipes is evaluated. Thereby, conventional difficulty of formulating a proper pipe thickness reducing estimation model formula in view of actual pipe material and pipe inner fluid state because of too many possibly influential parameters causing pipe thickness reducing due to erosion and corrosion, and conventional difficulty of performing highly reliable pipe thickness reducing management are overcome.

Thickness reducing management system for pipes in pipe lines

Nuclear fuels are taken from a nuclear reactor pressure vessel, a rail for running is mounted under the reactor pressure vessel drain piping in parallel with a horizontal portion of the reactor pressure vessel drain piping inside a pedestal positioned on the lower side of the reactor pressure vessel, an inspection apparatus is mounted on the rail, and the inspection apparatus is moved along the rail to inspect the reactor pressure vessel drain piping, whereby the reactor pressure vessel drain piping can be surely inspected while reducing radiation exposure to an inspector.

Growing community of inventors

Hitachi, Japan

Masakazu Hisatsune