Abstract: A method and system for reducing stress corrosion cracking in a hot water system, such as a nuclear reactor, by reducing the electrochemical corrosion potential of components exposed to high temperature water within the structure. The method comprises the steps of: providing a reducing species to the high temperature water; and providing a plurality of noble metal nanoparticles having a mean particle size of up to about 100 nm to the high temperature water during operation of the hot water system. The catalytic nanoparticles, which may comprise at least one noble metal, form a colloidal suspension in the high temperature water and provide a catalytic surface on which a reducing species reacts with least one oxidizing species present in the high temperature water. The concentration of the oxidizing species is reduced by reaction with the reducing species on the catalytic surface, thereby reducing the electrochemical corrosion potential of the component.

Abstract: Method for controlling erosion and cracking in a metal component of a nuclear reactor, particularly in the highly concentrated primary and secondary systems of a PWR, comprising creating a catalytic surface on the component; and generating a stoichiometric excess of reductant the water of the reactor to reduce the oxidant concentration at the surface to substantially zero.

Abstract: Method for controlling erosion and cracking in a metal component of a nuclear reactor, particularly in the highly concentrated primary and secondary systems of a PWR, comprising creating a catalytic surface on the component; and generating a stoichiometric excess of reductant the water of the reactor to reduce the oxidant concentration at the surface to substantially zero.

Abstract: A method of predicting component crack behavior in a nuclear reactor provides access to a crack growth behavior model over a global network. A user inputs water chemistry and material characteristics of a particular nuclear reactor and can perform crack growth rate predictions by accessing the behavior model over the computer network. A crack growth prediction profile or crack growth based result is output over the network according to an analysis by the behavior model.

Abstract: A method for mitigating general corrosion and crack initiation and growth on the surface of a metal components in a water-cooled nuclear reactor. A compound containing a non-noble metal such as zirconium or titanium is injected into the water of the reactor in the form of a solution or suspension. This compound decomposes under reactor thermal conditions to release ions or atoms of the non-noble metal which incorporate in the surfaces of the components, including the interior surfaces of any cracks formed therein. The preferred compounds are zirconium compounds such as zirconium acetylacetonate, zirconium nitrate and zirconyl nitrate. Zirconium incorporated in the oxided surface of a metal component will reduce the electrochemical corrosion potential at the surface to a level below the critical potential to protect against intergranular stress corrosion cracking without the addition of hydrogen.

Abstract: A method for improving the performance and longevity of coatings of metal deposited from aqueous solutions of inorganic, organic or oraganometallic metal compounds. The method involves co-deposition of noble metal or corrosion-inhibiting non-noble metal during growth of oxide film on a component made of alloy, e.g., stainless steels and nickel-based alloys. The result is a metal-doped oxide film having a relatively longer life in the reactor operating environment. In particular, incorporation of palladium into the film provides greatly increased catalytic life as compared to palladium coatings which lie on the oxide surface.

Abstract: A method for mitigating crack initiation and propagation on the surface of metal components in a water-cooled nuclear reactor. An electrically insulating coating doped with a noble metal is applied on the surfaces of IGSCC-susceptible reactor components. The preferred electrically insulating material is yttria-stabilized zirconia doped with palladium or platinum. The presence of an electrically insulating coating on the surface of the metal components shifts the corrosion potential in the negative direction without the addition of hydrogen. Corrosion potentials .ltoreq.-0.5 V.sub.SHE are believed to be achievable even at high oxidant concentrations and in the absence of hydrogen, although the coatings are believed to be particularly suited to applications where a reductant, such as hydrogen, is present.

Abstract: A method for mitigating crack initiation and propagation on the surface of metal components in a water-cooled nuclear reactor. An electrically insulating coating is applied on the surfaces of IGSCC-susceptible reactor components. The preferred electrically insulating material is yttria-stabilized zirconia. The presence of an electrically insulating coating on the surface of the metal components shifts the corrosion potential in the negative direction without the addition of hydrogen and in the absence of noble metal catalyst. Corrosion potentials .ltoreq.-0.5 V.sub.she can be achieved even at high oxidant concentrations and in the absence of hydrogen.

Abstract: An apparatus and a method for measuring and controlling the crack growth rate within a double cantilever beam type test specimen. The arms of the test specimen are fitted with a pressure-actuated bellows to induce a predetermined load and with a sensing assembly to provide feedback on the amount of beam displacement resulting from application of that load. In this manner a loaded test specimen may be remotely mounted and adjusted inside the reactor pressure vessel or piping of a nuclear reactor in order to maintain a stress intensity which is constant or which varies in a predetermined manner for inducing stress corrosion cracking or corrosion fatigue in the specimen.

Abstract: A high-chromium stainless steel alloy having improved resistance to stress corrosion cracking in high temperature water is comprised of, in weight percent; about 22 to 32 percent chromium, about 16 to 40 percent nickel, up to about 10 percent manganese, up to about 0.06 percent carbon, and the balance substantially iron. A preferred high-chromium alloy is further comprised of about 2 to 9 weight percent of a metal from the group consisting of titanium, niobium, tantalum, and mixtures thereof. Another preferred high-chromium alloy is further comprised of a platinum group metal in an effective amount to reduce the corrosion potential of the alloy in high-temperature water provided with hydrogen.

Abstract: A method for lowering the corrosion potential on components formed from carbon steel, alloy steel, stainless steel, nickel based alloys, or cobalt based alloys, and exposed to high-temperature water comprised of oxidizing species, comprising: providing a reducing species in the high temperature water that can combine with the oxidizing species, and forming the component to have a catalytic layer of a platinum group metal.