31results about How to "Prevents stress corrosion cracking" patented technology

In a method of reducing corrosion of a material constituting a nuclear reactor structure, an electrochemical corrosion potential is controlled by injecting a solution or a suspension containing a substance generating an excitation current by an action of at least one of radiation, light, and heat existing in a nuclear reactor, or a metal or a metallic compound forming the substance generating the excitation current under the condition in the nuclear reactor to allow the substance generating the excitation current to adhere to the surface of the nuclear reactor structural material, and by injecting hydrogen in cooling water of the nuclear reactor while controlling the hydrogen concentration in a feed water.

A device for isolating, accumulating, indicating and venting gas in a fluid system pipe includes a coupling affixed to a system pipe. The coupling includes an isolation valve. A standpipe is attached to the coupling. The standpipe holds a float trapped between a flow retaining orifice and a closed upper end save for an angled hole therein that allows gas to flow around the float. An indicator exterior to the pipe indicates the float's level in the standpipe regardless of system pressure changes. A vent valve attached above the standpipe allows controlled ventilation of the gas flowing from the system pipe through the standpipe and through the vent valve. Accumulation of gas from the system pipe lowers the float in the standpipe, at which point the user vents the gas, causing the float to rise with the rising fluid level.

A control rod for nuclear reactors includes four wings including neutron absorbers containing hafnium, a front end structural member which has a cross shape in cross section and includes brackets bonded to the leading ends of the wings, and a terminal end structural member which has a cross shape in cross section and includes brackets bonded to the tailing ends of the wings. The four wings are bonded to a wing-bonding member including a cross-shaped center shaft so as to form a cross shape. The front end structural member and the wing-bonding member are made of a zirconium alloy. The wings include neutron-absorbing plates having neutron-absorbing portions and each have an outer surface which is opposed to a fuel assembly and at which a hafnium-zircaloy composite member covered with zircaloy is disposed. The neutron-absorbing plates are opposed to each other with trap spaces disposed therebetween.

The alloy powder capable of producing compression stress in the fused-on layer consists of Cr 6.0-12.0 wt%, Ni 5.0-11.0 wt%, Mn 0.5-1.8 wt%, Mo 0.1-0.9 wt%, Nb 0.1- 0.9 wt%, Ti 0.1-0.9 wt%, Si 0.1-0.9 wt%, except Fe. It has grain size of 50-200 microns, solid phase change temperature after melting and solidifying of 100-300 deg.c, and structure comprising martensite in 50-90 % and austenite in 10-50 %. The present invention is used in raising the fatigue resistance, stress corrosion resistance, safety and service life of iron and steel material, mechanical structure and equipment. The method and material of the present invention may be used in producing composite material product with compression stress in the surface.

The invention relates to a tube plate of a steam generator and a preparation method thereof. The tube plate of the steam generator supports heat transfer tubes of the steam generator. In particular, it relates to a steam generator tube plate with an anti-corrosion layer and a preparation method thereof. Specifically, the steam generator tube sheet with an anti-corrosion layer includes: a steam generator tube sheet, which supports the heat transfer tube of the vaporizer; and a corrosion-resistant metal, which is plated on the surface of the primary side tube sheet and the surface of the secondary side tube sheet superior. In addition, a method for preparing a steam generator tube sheet with an anti-corrosion layer includes the steps of: coating the surface of the primary side tube sheet and the surface of the secondary side tube sheet with a corrosion-resistant metal; heat-treating the above-mentioned coated tube sheet; and drilling holes, forming heat transfer tube mounting holes on the heat-treated tube sheet; thereby inhibiting the corrosion of the surface of the primary side tube sheet and the surface of the secondary side tube sheet, and preventing the depression and stress corrosion cracking of the heat transfer tube, thereby improving The reliability of the steam generator.