General Electric Company

Other

Ilc Technology, Inc.

Mickey O Marlowe

Ronald B Adamson

Herman S Rosenbaum

Cedric D Williams

Daniel Reese Lutz

Richard A Proebstle

John H Davies

John Frederick Schardt

Eric B Johansson

Gerald M Gordon

Anthony P Reese

Kenneth W Lay

Joseph S Armijo

Lowell A Noble

Alvin J Jacobs

Charles B Patterson, Jr

Elias Plaza-Meyer

Dale H Klahn

Leonard N Grossman

Trevor C Rowland

An improved fuel element for use in a nuclear reactor comprised of a central core of nuclear material, which is surrounded by a composite cladding. The cladding has an outer metallic tubular portion comprised of well-known cladding alloys used for such purposes. Metallurgically bonded to the outer metallic tubular portion is a commercially pure zirconium microalloyed with a controlled quantity of iron. The zirconium microalloyed with iron produced an inner metallic barrier having a beneficial balance between stress corrosion crack resistance and corrosion resistance while retaining other beneficial properties of pure zirconium, such as ductility.

Cladding for use in nuclear reactors having improved resistance to stress corrosion cracking and corrosion

Improved method of sintering for the manufacture of nuclear fuel comprising a fissionable ceramic material including a silica containing additive. The method includes controlling the sintering atmosphere to impede loss through vaporization of the silica.

Controlled atmosphere sintering process for urania containing silica additive

An improved test for determining densification characteristics of nuclear fuel including a fissionable ceramic material is disclosed. The test includes controlling the testing atmosphere to impede loss through vaporization of silica and in turn density reduction due to compositional changes.

Densification test procedure for urania

Zirconium-based components for nuclear reactors are disclosed whereby a rare earth or other metal which preferentially concentrates hydrogen when in contact with zirconium is dispersed as a second phase throughout a zirconium-based matrix. The morphology and distribution of the two-phase material is controlled such that the second phase, internal hydrogen absorbing particles, are provided as spherical particles, randomly distributed, to minimize the effects of the occluded hydrogen.

Zirconium-based two-phase alloys for hydride resistant nuclear reactor

An improved stainless steel composition and an improved stainless Ni-based alloy are disclosed for use in nuclear reactor environments. The improved stainless alloys include a stainless steel and a stainless nickel based alloy that are particularly well adapted for use in reactor components that are positioned adjacent to components formed from a zirconium based metal. The improved stainless steel is an austenitic stainless steel material that include less than approximately 0.2 percent manganese by weight, but does include sufficient austenitic stabilizer to prevent a martensitic transformation during fabrication or use in a reactor environment. In one preferred embodiment, the stainless alloy is formed without any significant amount of manganese.

Reduction of manganese content of stainless alloys to mitigate corrosion

A method is provided for preparing a cladding tube having an outer substrate, an intermediate zirconium barrier layer, and an inner liner. The method includes the following steps: (a) bonding an inner liner alloy sheath exterior circumferential surface to a zirconium sheath interior circumferential surface to form a barrier/inner liner sheath, and (b) bonding the exterior surface of the zirconium sheath on the barrier/inner liner sheath to the interior circumferential surface of an outer substrate alloy tube to form the cladding tube. Alternatively, the method includes the following steps: (a) bonding the zirconium sheath exterior circumferential surface to the outer substrate alloy tube interior circumferential surface to form a substrate tube/barrier sheath, and (b) bonding the exterior circumferential surface of the inner liner alloy sheath to the interior circumferential surface of the zirconium sheath of the substrate tube/barrier sheath to form said cladding tube. In either approach the tube produced by step (a) is heat treated before step (b) is performed. The bonding steps are performed by extrusion and sometimes hot isostatic pressing.

Two-step process for bonding the elements of a three-layer cladding tube

A cladding tube for use in holding fissionable material in a water cooled nuclear reactor is provided. The cladding tube includes inner and outer circumferential regions, and including (1) a substrate defining the outer circumferential region, and (2) an inner liner defining the inner circumferential region. The inner liner is made from a zirconium alloy having at least one alloying element which promotes hydrogen absorption in a concentration of between about 1 and 15 weight percent. The hydrogen absorption promoting element can be one of the following: nickel, chromium, iron, zinc, vanadium, gallium, yttrium, palladium, platinum, or aluminum.

Nuclear fuel cladding with hydrogen absorbing inner liner

The disclosed invention consists of a ceramic form of fuel for a nuclear reactor comprising an oxide of a fissionable element and containing therein a consumable neutron absorbing agent. The ceramic fissionable fuel product provides longer fuel performance in nuclear reactor service.

Fissionable nuclear fuel composition

An improved nuclear fuel element for service in power generating, water cooled nuclear reactors, comprising a fuel cladding container of an alloy of zirconium provided with a barrier lining of unalloyed zirconium metal metallurgically bonded to the container's inner surface, and enclosed therein fissionable nuclear fuel including an additive of aluminum silicate.

Nuclear fuel element

A mixture of uranium dioxide and additive of aluminosilicate composition is formed into a compact and sintered to produce a nuclear fuel wherein the uranium dioxide grains have an average grain size of at least about 20 microns and wherein substantially all of the grains are each enveloped by glassy aluminosilicate phase.

Nuclear fuel

The invention is directed to an axially alignable nuclear fuel pellet of the type stacked in end-to-end relationship within a tubular cladding. Experience has shown that fuel cladding failures can occur at pellet interface locations due to mechanical interaction between misaligned fuel pellets and the cladding. Mechanical interaction between the cladding and the fuel pellets loads the cladding and causes increased cladding stresses. Nuclear fuel pellets constructed according to the invention are provided with an end structure that increases plastic deformation of the pellets at the interface between pellets so that lower alignment forces are required to straighten axially misaligned pellets. Plastic deformation of the pellet ends results in less interaction between the cladding and the fuel pellets and significantly lowers cladding stresses. The geometry of pellets constructed according to the invention also reduces alignment forces required to straighten fuel pellets that are tilted within the cladding. Plastic deformation of the pellets at the pellet interfaces in both axial and transverse directions is increased by providing pellets with at least one end face having a centrally-disposed raised area of generally convex shape so that the mean temperature and shear stress of the contact area is much higher than that of prior art pellets. Fuel pellets constructed according to the invention may be provided with one end having a centrally-disposed raised area and the opposite end flat or the opposite end may also be provided with a centrally-disposed raised area, or the opposite end may be provided wth a centrally-disposed depression having a depth less than the height of the raised area of an adjacent pellet.

Axially alignable nuclear fuel pellets

A process for polishing surfaces of sapphire or similar materials to remove surface imperfections visible at magnifications of 1,000X or higher regardless of the shape of the surface, is disclosed, which process comprises the steps of heating the material to an elevated temperature and exposing the surface to be polished to a static hydrogen environment.

Growing community of inventors

Fremont, CA, United States of America

Mickey O Marlowe