Abstract: A wear resistant coating (50) for fuel rod cladding (20) comprises a ceramic material (52) which is premixed with a glass (54). The cladding tube is heated and the ceramic/glass mixture is flame sprayed onto the cladding tube. The coating is applied to lower portions of the fuel rods (10) in the area of the first support grid (12) where debris tends to fret the fuel rod.

Abstract: A burnable-absorber-containing zirconium alloy is described for application to the inside surface of cladding tubes for light water nuclear reactors. The alloy comprises naturally occurring erbium in a range from a measurable amount up to about 20 wt. % or isotopically purified erbium-167 in a range from a measurable amount up to about 5 wt. %; tin in a range from a measurable amount up to about 0.5 wt. %; iron in a range from a measurable amount up to about 0.2 wt. %; chromium in a range from a measurable amount up to about 0.1 wt. %; niobium in a range from a measurable amount up to about 0.1 wt. %; silicon in a range from about 50 to about 120 parts per million ("ppm"); oxygen in a range from a measurable amount up to about 800 ppm; and the balance zirconium. Such an alloy provides an effective absorber material for reactor control, while providing adequate mechanical properties and corrosion resistance for the intended application.

Abstract: Methods and apparatus for improving fretting resistance of zirconium alloy components formed into a shape for use in a nuclear reactor are disclosed in which at least a portion of the outer surface of a component is reacted with material selected from the group consisting of carbon, nitrogen, oxygen and combinations of the foregoing at a temperature below about 700.degree. C. to form a wear resistant layer on the surface of the component.

Abstract: A cladding tube for nuclear fuel having an outer elongated cladding tube and a zirconium liner which lines the outer cladding tube, the inner wall of the liner having an inner diffusion portion of a zirconium based alloy of tin and/or vanadium.

Abstract: A structural part for a nuclear reactor fuel assembly includes a zirconium alloy material having at least one alloy ingredient selected from the group consisting of oxygen and silicon, a tin alloy ingredient, at least one alloy ingredient selected from the group consisting of iron, chromium and nickel, and a remainder of zirconium and unavoidable contaminants. The zirconium alloy material has a content of the oxygen in a range of substantially from 700 to 2000 ppm, a content of the silicon of substantially up to 150 ppm, a content of the iron in a range of substantially from 0.07 to 0.5% by weight, a content of the chromium in a range of substantially from 0.05 to 0.35% by weight, a content of the nickel of substantially up to 0.1% by weight, and a content of the tin in a range of substantially from 0.8 to 1.7% by weight.

Abstract: A fuel element (10) for a nuclear reactor having a zirconium-tin alloy cladding tube (20), with a thin coating (30) of a burnable poison consisting of an enriched boron particles sealed in a boron-containing glass or glass compound deposited from a liquid sol-gel.

Abstract: A corrosion resistant metallic coating (60) of zirconium nitride is applied to the cladding tube (40) of a nuclear fuel rod (20). The zirconium nitride is reactively deposited on a zirconium-alloy cladding tube by a cathodic arc plasma deposition process. The zirconium nitride coating provides superior wear test results and enhances the corrosion resistance of the cladding tube.

Abstract: A fuel assembly for a nuclear reactor comprising a fuel cladding tube of three-layer structure having an outer surface in contact with reactor water of the nuclear reactor, an inner surface layer in contact with the nuclear fuel, and an intermediate layer interposed between the outer surface layer and the inner surface layer. the outer surface layer is made of a Zr-based alloy containing Nb, Sn and Mo. The inner surface layer is made of pure zirconium. The intermediate layer is made of a high ductility alloy which is higher in ductility than the outer surface layer and is higher in strength than the inner surface layer.

Abstract: Nuclear fuel compacts, containing thousands of individually coated fuel particles in a carbonaceous matrix, are provided with an overcoating of silicon carbide which can be readily inspected for defects. This overcoating helps retain fission products within the compact should any of the fuel particles have damaged or defective coatings, and provides an outer secondary barrier that can be 100% inspected.

Abstract: A corrosion resistant zirconium alloy is comprised of, in weight percent, about 0.1 to less than 0.5 percent bismuth, about 0.1 to less than 0.5 percent niobium, and the balance substantially zirconium. Preferably, niobium is about 0.1 to 3 weight percent. The alloys have improved corrosion resistance as compared to the moderate-purity sponge zirconium while maintaining a ductility comparable to sponge zirconium.

Abstract: A fuel rod for a water cooled nuclear reactor comprises a cladding made of a continuous wound ceramic fiber tube. The wound fibers are impregnated with a matrix to achieve a required density and exposed to ammonia gas to create a solid gel. The gel is fired to form a ceramic composite having desirable thermal properties, strength, corrosion resistance, toughness and neutron capture cross-section.

Abstract: A wear resistant coating (50) for fuel rod cladding (20) comprises a ceramic material (52) which is premixed with a glass (54). The cladding tube is heated and the ceramic/glass mixture is flame sprayed onto the cladding tube. The coating is applied to lower portions of the fuel rods (10) in the area of the first support grid (12) where debris tends to fret the fuel rod.

Abstract: An organometallic chromium compound in the gaseous phase is brought into contact with a substrate consisting of the inner surface of the zirconium alloy tubular cladding (5) of the fuel element, or the outer surface of the pellets of fuel material, the substrate being kept at a temperature between 300.degree. and 600.degree. C. The organo metallic compound may consist of chromium acetylacetonate. The process enables a chromium oxide coating to be obtained inside the tubular cladding (5) and/or on the outer surface of the nuclear fuel pellets. Pellet/cladding interaction is thus prevented or limited when this fuel element is used in the reactor.

Abstract: A nuclear fuel element for a high temperature gas nuclear reactor that has an average operating temperature in excess of 2000.degree. C., and a method of making such a fuel element. The fuel element is characterized by having fissionable fuel material localized and stabilized within pores of a carbon or graphite member by melting the fissionable material to cause it to chemically react with the carbon walls of the pores. The fissionable fuel material is further stabilized and localized within the pores of the graphite member by providing one or more coatings of pyrolytic carbon or diamond surrounding the porous graphite member so that each layer defines a successive barrier against migration of the fissionable fuel from the pores, and so that the outermost layer of pyrolytic carbon or diamond forms a barrier between the fissionable material and the moderating gases used in an associated high temperature gas reactor.

Abstract: The present invention relates to the control of grain structure in unalloyed zirconium metal and, more particularly, to the control of grain structure in zirconium metals containing less than 300 parts per million Fe.

Abstract: Zirconium-based corrosion resistant alloys for use primarily as a cladding material for fuel rods in a boiling water nuclear reactor consist essentially of by weight percent about 0.5 to 2.0 percent tin, about 0.24 to 0.40 percent of a solute composed of copper, nickel and iron, wherein the copper is at least 0.05 percent, and the balance zirconium. Nuclear fuel elements for use in the core of a nuclear reactor have improved corrosion resistant cladding made from these zirconium alloys or composite claddings have a surface layer of the corrosion resistant zirconium alloys metallurgically bonded to the outside surface of a Zircaloy alloy tube. The claddings may contain an inner barrier layer of moderate purity zirconium metallurgically bonded on the inside surface of the cladding to provide protection from fission products and gaseous impurities generated by the enclosed nuclear fuel.

Abstract: A nuclear fuel element for use in the core of a nuclear reactor is disclosed having an improved corrosion resistant cladding. The cladding is comprised of zirconium alloys containing in weight percent 0.5 to 2.0 percent tin, or 0.5 to 2.5 percent bismuth, or 0.5 to 2.5 percent bismuth and tin, and about 0.5 to 1.0 percent of a solute composed of a member selected from the group consisting of molybdenum, niobium, tellurium and mixtures thereof, and the balance zirconium. Composite claddings are disclosed having a surface layer of one of the corrosion resistant zirconium alloys metallurgically bonded to a Zircaloy alloy tube. Claddings may contain an inner barrier layer of a moderate purity zirconium metallurgically bonded on the inside surface of the cladding to provide protection from fission products and gaseous impurities generated by the enclosed nuclear fuel.

Abstract: The fuel rod comprises a sheath having an inner tubular layer and an outer surface layer composed of zirconium alloys which differ from each other. The surface layer, whose thickness is between 10 to 25% of the total thickness of the wall of the sheath, is constituted by a zirconium-base alloy containing by weight 0.35 to 0.65% tin, 0.20 to 0.65% iron, 0.09 to 0.16% oxygen and niobium in a proportion of 0.35 to 0.65% or vanadium in a proportion of 0.25 to 0.35%. The inner layer may be constituted by an alloy such as Zircaloy 4 or a zirconium-niobium alloy.

Abstract: Zirconium-based corrosion resistant alloys for use primarily as a cladding material for fuel rods in a boiling water nuclear reactor consist essentially of by weight percent about 0.5 to 2.0 percent thin, about 0.24 to 0.40 percent of a solute composed of copper, nickel and iron, wherein the copper is at least 0.05 percent, and the balance zirconium. Nuclear fuel elements for use in the core of a nuclear reactor have improved corrosion resistant cladding made from these zirconium alloys or composite claddings have a surface layer of the corrosion resistant zirconium alloys metallurgically bonded to the outside surface of a Zircaloy alloy tube. The claddings may contain an inner barrier layer of moderate purity zirconium metallurigcally bonded on the inside surface of the cladding to procide protection from fission products and gaseous impurities generated by the enclosed nuclear fuel.

Abstract: A method of inhibiting deleterious reactions between metallic fissionable fuel for nuclear reactors and stainless steel containers for housing such fuel comprising imposing an expendable body of alloying metal intermediate the fuel and container is disclosed. The disclosure also includes an improved nuclear fuel element comprising metal alloy fuel housed within stainless steel containers having a body of zirconium metal interposed between the fuel and containers.

Abstract: A fuel rod for a nuclear reactor fuel assembly includes a cladding tube having an outer surface and a given total wall thickness. Nuclear fuel is disposed in the cladding tube. The cladding tube is formed of a first zirconium alloy which may have alloy components of from 1.2 to 2% by weight of tin, 0.07 to 0.2% by weight of iron, 0.05 to 0.15% by weight of chromium, 0.03 to 0.08% by weight of nickel, 0.07 to 0.15% by weight of oxygen, and a total percent by weight for the alloy components of iron, chromium and nickel in a range of from 0.18 to 0.38% by weight. The first zirconium alloy may also have alloy components of from 1.2 to 2% by weight of tin, 0.18 to 0.24% by weight of iron, 0.07 to 0.13% by weight of chromium, 0.10 to 0.16% by weight of oxygen, and a total percentage by weight for the components of iron and chromium in a range of from 0.28 to 0.37% by weight.

Abstract: A dispersion strengthened ferritic steel cladding tube for use in a nuclear reactor and having a double-layer structure is provided. The cladding tube comprises a tube body made of a dispersion strengthened ferritic steel having a ceramic dispersed therein and containing 8 to 13% by weight of chromium. The inner surface of the tube body is lined with a ferritic steel containing 18 to 30% by weight of chromium. The cladding tube has not only excellent compatibility with a mixed oxide fuel but also excellent high temperature strength and swelling resistance.A method of producing the cladding tube using powder metallurgy is also provided.

Abstract: This invention describes a tubular water reactor fuel cladding having an outer cylindrical layer composed of a conventional zirconium base alloy. Bonded to the outer cylindrical layer is a second layer composed of an alloy selected from the group of zirconium base alloys consisting of: about 0.19 to 0.6 wt. % tin, about 0.19 to 0.5 wt. % iron, and about 100 to 700 ppm oxygen; or about 0.4 to 0.6 wt. % tin, about 0.1 to 0.3 wt. % iron, about 0.1 to 0.3 wt. % nickel, and about 100 to 700 ppm oxygen.

Abstract: Nuclear fuel elements for use in the core of a nuclear reactor include an improved composite cladding having a zirconium barrier layer metallurgically bonded on the inside surface of a zirconium alloy tube, wherein the inside surface of the barrier is alloyed with preselected elemental impurities to improve oxidation resistance. The zirconium barrier layer forms a shield between the zirconium alloy tube and a core of nuclear fuel material enclosed in the composite cladding. The alloy layer formed on the barrier surface acts to inhibit cracking during the tube production fabrication step and limits oxidation in the event that the cladding is breached during operation of the reactor, allowing the entrance of water or steam into the fuel element.

Abstract: Disclosed are a cladding tube for a nuclear fuel and a nuclear fuel element incorporating the cladding tube. The cladding tube consists of an inner zirconium liner layer and an outer zirconium alloy layer. The cladding tube has at least one of the following features: (I) the ratio a/b of the oxygen content a to iron content b in the zirconium liner layer is greater than 1.0, (II) the zirconium liner layer is made of a zirconium into the matrix of which impurities are dissolved, and (III) the second phase particles having microscopic sizes and dispersed in the inner surface of the zirconium liner layer and/or the outer surface of the zirconium alloy layer have been removed substantially. Owing to these features, undesirable stress corrosion cracking and local corrosion are remarkably suppressed in the cladding tube and the nuclear fuel element of the invention.

Abstract: For improving the corrosion resistance of the sheaths of fuel rods used in water cooled and moderated reactors, part at least of the outer surface of the sheath is coated with a dense and adhering carbon layer having a thickness of from 0.1.mu. to 5.mu.. The layer may be deposited by radiofrequency reactive sputtering in a lower alkyl containing atmosphere.

Abstract: This is a process for producing material for lining reactor fuel element claddings. Rather than using unalloyed zirconium, this invention provides for an alloy liner for the cladding. The process uses ultra-slow electron beam melting of zirconium, to give very low metallic impurities to reduce solid solution strengthening and second phase formation and property variability from lot to lot, while using alloying to reduce the susceptibility to steam corrosion. Oxygen is controlled to a very low level as well, and preferably only 0.1-0.4 tin is added to provide a low, but fabricable, hardness in the alloyed liner material.

Abstract: This is a material for lining reactor fuel element cladding. Rather than using unalloyed zirconium, this invention utilized for a 0.1-4% tin alloy liner for the cladding. The very low metallic impurities to reduce solid solution strengthening and second phase formation and property variability from lot to lot, while using alloying to reduce the susceptibility to steam corrosion. Preferably, oxygen is controlled to a very low level as well, to provide a low, but fabricable, hardness in the alloyed liner material.

Abstract: This is a process for producing material for lining reactor fuel element claddings. Rather than using unalloyed zirconium, this invention provides for an alloy liner for the cladding. The process uses electron beam melting of zirconium, to give very low metallic impurities to reduce solid solution strengthening and second phase formation and property variability from lot to lot, while using alloying to reduce the susceptibility to steam corrosion. Preferably, oxygen is controlled to a low level as well, to provide a low, but fabricable, hardness in the alloyed liner material.

Abstract: This invention relates to a tubular water reactor fuel cladding having an outer cylindrical layer composed of a conventional zirconium base alloy. Bonded to the outer layer is a second, inner layer composed of an alloy consisting essentially of: about 0.1 to 0.3 wt. % tin; about 0.05 to 0.2 wt. % iron; about 0.05 to 0.4 wt. % niobium; about 0.03 to 0.1 wt. % of either chromium or nickel, alone or in combination with each other; while keeping the sum of the iron chromium and nickel contents below 0.25 wt. %; 300 to 1200 ppm oxygen; and the balance essentially zirconium. The inner layer is characterized by excellent resistance to PCI crack propagation, excellent aqueous corrosion resistance and a fully recrystallized microstructure.

Abstract: An elongated nuclear fuel cladding tube is provided with at least two annular concentric layers which are bonded to each other. The inner layer is composed of a zirconium base alloy. The outer layer is composed of a titanium base material exhibiting excellent corrosion resistance in elevated temperature and pressure aqueous environments.

Abstract: Fuel rod cladding tube having an inner tubular layer of a zirconium alloy with alloying components of 1.2 to 1.7% tin, 0.07 to 0.2% iron, 0.05 to 0.15% chromium, 0.03 to 0.08% nickel, 0.07 to 0.15% oxygen, with the sum of percentages of iron, chromium and nickel in the range of 0.18 to 0.38%; or with the alloying components 1.2 to 1.7% tin, 0.18 to 0.24% iron, 0.07 to 0.13% chromium, 0.10 to 0.16% oxygen, with the sum of percentages of iron and chromium in the range of 0.28 to 0.37%; and with the inner tubular layer having an outside surface layer of another zirconium alloy with a layer thickness of 5 to 20% of the cladding tube as well as with 0 to 1% iron as an alloying component and with at least one alloying component from the group of: vanadium with 0.1 to 1% by weight, platinum with 0.1 to 1% by weight, and copper with 1 to 3% by weight.

Abstract: A nuclear fuel rod cladding having a burnable absorber integrally incorporated therein has an outer tubular layer of a zirconium alloy; an intermediate layer, of a thickness less than the outer tubular layer, of a zirconium alloy containing a boron-containing burnable absorber; and an inner layer, of a thickness less than the intermediate layer, of zirconium metal. The layers are bonded together to form a cladding for the containment of nuclear fuel.

Abstract: A cadmium oxide glazed nuclear fuel pellet and glazing composition therefor is disclosed which controls the reactivity and extends the operating life cycle of a nuclear reactor while increasing the rate of burnout of the burnable absorber and reducing the amount of undersirable gases produced therefrom. The glaze forming composition comprises at least about 0.5 percent by weight cadmium oxide as a burnable absorber, i.e., cadmium-113 isotope, and at least one glaze forming oxide. The glaze constituents are formed into a slurry and a nuclear fuel pellet is dipped into the slurry to produce a hard refractory glaze upon firing and cooling.

Abstract: Described herein is a composite nuclear fuel rod cladding tube which includes two concentric layers of zirconium base alloys metallurgically bonded to each other. The outer layer is composed of a conventional zirconium base alloy having high strength and excellent aqueous corrosion resistance. The inner layer is composed of a second zirconium base alloy containing about 0.2 to 0.6 wt. % tin, about 0.03 to 0.11 wt. % iron and up to about 350 ppm oxygen. This second alloy while also having excellent aqueous corrosion resistance, is further characterized by the ability to prevent the propagation of cracks initiated during reactor operation due to pellet-cladding interaction.

Abstract: A fuel pellet for a nuclear core fuel rod for use in a nuclear reactor fuel assembly having a predetermined radial distribution of burnable poison, fertile, and fissile nuclear material to provide the desired control of reactivity of the fuel pellet with the minimum amount of burnable poison material and to provide control of the nuclear reactivity of the fuel assembly.

Abstract: The present invention pertains to zirconium base alloys containing about 0.1 to 0.6 weight percent tin; about 0.07 to 0.24 weight percent iron; about 0.05 to 0.15 weight percent chromium; and up to about 0.05 weight percent nickel. The balance of the alloy is zirconium with incidental impurities. The levels of the incidental impurity, oxygen, is controlled to a level of less than about 350 ppm. These alloys have been designed to minimize the adverse effects of pellet-clad interaction, when they are used as a liner bonded to the inside surface of water reactor nuclear fuel cladding. Specific cladding and fuel element designs according to the present invention are described.

Abstract: A hydride blister-resistant nuclear fuel rod cladding has a tubular cladding formed from a zirconium-based alloy which has a thin nickel base film, of a thickness of about 0.01 to 5 microns distributed over between 1-40 percent of the area of the internal surface of the tubular cladding. The dispersed nickel base film provides multiple sites for hydride transport from the interior of the nuclear fuel rod and prevents localized hydride transport and resulting hydride blistering.

Abstract: For the production of plate-shaped fuel elements for research reactors having charges of more than 26 volume % of uranium compound in the aluminum matrix according to the known picture frame technique, 0.01 to 0.3 mm thick aluminum layers are applied by rolling to the picture before inserting it into the frame in order to avoid dragging the uranium into the fuel-free zones.

Abstract: Described herein is a water reactor composite nuclear fuel rod cladding tube which includes two concentric metallic layers metallurgically bonded to each other. The outer layer is composed of a conventional zirconium base alloy having high strength and excellent aqueous corrosion resistance. The inner layer is composed of: a low oxygen, BCC crystal structure niobium base material, containing less than about 59 w/o zirconium; or a ferritic stainless steel. This inner layer material is characterized by the ability to prevent the propagation of cracks initiated during reactor operation due to pellet-cladding interaction.

Abstract: A fuel rod for a nuclear reactor comprises a cladding tube of a zirconium-based alloy, on the internal surface of which there is arranged a layer of zirconium containing 0.1-1 per cent by weight tin. The fuel rod contains a nuclear fuel preferably of uranium dioxide.

Abstract: A nuclear reactor component such as a fuel rod, burnable absorber rod, or neutron absorber rod, comprising a hermetically sealed metallic tube containing a solid material such as a nuclear fuel, burnable absorber, or neutron absorber, within a helium atmosphere, which solid material will release tritium into the helium atmosphere, has added thereto about 2-3 percent by volume of a gas, selected from oxygen, carbon monoxide and carbon dioxide. The addition of this gas to the helium atmosphere is effective to form an oxide layer on the inner surface of the metallic tube and significantly reduce the permeation of tritium through the metallic tube, such that the tritium is retained within the reactor component.

Abstract: A burnable absorber coated nuclear fuel. A fissionable material nuclear fuel substrate is at least partially covered by a burnable absorber layer. A hydrophobic material overcoat layer generally covers the burnable absorber layer and is bonded directly to it.

Abstract: An improved fuel pin cladding, particularly adapted for use in breeder reactors, consisting of composite tubing with austenitic steel on the outer portion of the thickness of the tube wall and with nickel and/or ferritic material on the inner portion of the thickness of the tube wall. The nickel forms a sacrificial barrier as it reacts with certain fission products thereby reducing fission product activity at the austenitic steel interface. The ferritic material forms a preventive barrier for the austenitic steel as it is immune to liquid metal embrittlement. The improved cladding permits the use of high density fuel which in turn leads to a better breeding ratio in breeder reactors, and will increase the threshold at which failure occurs during temperature transients.

Abstract: A device for shutting down a nuclear reactor during an undercooling or overpower event, whether or not the reactor's scram system operates properly. This is accomplished by double-clad fuel safety rods positioned at various locations throughout the reactor core, wherein melting of a secondary internal cladding of the rod allows the fuel column therein to shift from the reactor core to place the reactor in a subcritical condition.

Abstract: An improved method for producing nuclear fuel containers of a composite construction having components providing therein a barrier system for resisting destructive action by volatile fission products or impurities and also interdiffusion of metal constituents, and the product thereof. The composite nuclear fuel containers of the method comprise a casing of zirconium or alloy thereof with a layer of copper overlying an oxidized surface portion of the zirconium or alloy thereof.

Abstract: A nuclear fission electrical generator for extracting electrical power from fissionable material having semi-conductor characteristics without the necessity of an intervening thermal energy. Unwanted, randomly created electron-hole pairs are depleted from the semiconductor material. Phthalocyanine semiconductor are suitable, and uranium phthalocyanine is particularly suitable for use in this invention.

Abstract: A copper barrier type, nuclear fuel cladding is produced by forming an oxide layer on the inner wall surface of a tube of zirconium or zirconium alloy and then applying electroless copper plating to the oxide layer with a solution containing at least a copper salt, a complexing agent, a reducing agent, and 2,2'-dipyridyl, or further together with polyalkylene glycol as a plating solution. A good adhesiveness is obtained between the copper barrier layer and the oxide layer.