General Electric Company

Global Nuclear Fuel - Americas, LLC

Other

Ge-hitachi Nuclear Energy Americas LLC

Daniel Reese Lutz

Young Jin Kim

Ronald B Adamson

John Frederick Schardt

David W White

Yang-Pi Lin

Gerald A Potts

Mickey O Marlowe

Joseph S Armijo

Cedric D Williams

Robert B Elkins

Herman S Rosenbaum

Mark Andrew Dubecky

Sheikh Tahir Mahmood

Hiroaki Kagami

Hideyuki Mukai

David Michael Farkas

An alloy according to example embodiments of the present invention may include zirconium, tin, iron, chromium, and nickel, with a majority of the alloy being zirconium. The composition of the alloy may be about 0.85-2.00% tin by weight, about 0.15-0.30% iron by weight, about 0.40-0.75% chromium by weight, and less than 0.01% nickel by weight. The alloy may further include 0.004-0.020% silicon by weight, 0.004-0.020% carbon by weight, and/or 0.05-0.20% oxygen by weight. Accordingly, the alloy exhibits reduced hydrogen absorption and improved corrosion resistance and may be used to form a fuel assembly component.

Zirconium alloys exhibiting reduced hydrogen absorption

Disclosed herein are zirconium-based alloys and methods of fabricating nuclear reactor components, particularly fuel cladding tubes, from such alloys that exhibit improved corrosion resistance in aggressive coolant compositions. The fabrication steps include a late-stage &#x3b2;-treatment on the outer region of the tubes. The zirconium-based alloys will include between about 1.30 and 1.60 wt % tin; between about 0.06 and 0.15 wt % chromium; between about 0.16 and 0.24 wt % iron, and between 0.05 and 0.08 wt % nickel, with the total content of the iron, chromium and nickel comprising above about 0.31 wt % of the alloy and will be characterized by second phase precipitates having an average size typically less than about 40 nm. The final finished cladding will have a surface roughness of less than about 0.50 &#x3bc;m Ra and preferably less then about 0.10 &#x3bc;m Ra.

Zirconium alloy fuel cladding for operation in aggressive water chemistry

Example embodiments are directed to fuel assembly components and nuclear fuel bundles including the fuel assembly components. Example embodiments of a fuel assembly component may include a cylindrical device having first and second ends and a mounting assembly on the first end of the cylindrical device configured to attach to and detach from a partial length fuel rod. Example embodiments of a nuclear fuel bundle may include an upper tie plate, a lower tie plate, at least one full-length fuel rod, at least one partial length fuel rod, and a fuel assembly component.

Detachable nuclear reactor fuel assembly component

A zirconium alloy suitable for forming reactor components that exhibit reduced irradiation growth and improved corrosion resistance during operation of a light water reactor (LWR), for example, a boiling water reactor (BWR). During operation of the reactor, the reactor components will be exposed to a strong, and frequently asymmetrical, radiation fields sufficient to induce or accelerate corrosion of the irradiated alloy surfaces within the reactor core. Reactor components fabricated from the disclosed zirconium alloy will also tend to exhibit an improved tolerance for cold-working during fabrication of the component, thereby simplifying the fabrication of such components by reducing or eliminating subsequent thermal processing, for example, anneals, without unduly degrading the performance of the finished component.

LWR flow channel with reduced susceptibility to deformation and control blade interference under exposure to neutron radiation and corrosion fields

Disclosed herein are zirconium-based alloys that may be fabricated to form nuclear reactor components, particularly fuel cladding tubes, that exhibit sufficient corrosion resistance and hydrogen absorption characteristics, without requiring a late stage &#x3b1;+&#x3b2; or &#x3b2;-quenching processes. The zirconium-base alloys will include between about 1.30-1.60 wt % tin; 0.0975-0.15 wt % chromium; 0.16-0.24 wt % iron; and up to about 0.08 wt % nickel, with the total content of the iron, chromium and nickel comprising at least about 0.3175 wt % of the alloy. The resulting components will exhibit a surface region having a mean precipitate sizing of between about 50 and 100 nm and a Sigma A of less than about 2&#xd7;10hour with the workpiece processing generally being limited to temperatures below 680&#xb0; C. for extrusion and below 625&#xb0; C. for all other operations, thereby simplifying the fabrication of the nuclear reactor components while providing corrosion resistance comparable with conventional alloys.

Non-heat treated zirconium alloy fuel cladding and a method of manufacturing the same

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

A neutron radiography camera operates in cooperation with a neutron beam source for determining hydrogen content of irradiated BWR fuel elements. The camera implements the method using a notched neutron spectrum filter to determine the hydrogen content. The camera is specifically configured to take advantage of the tubular geometry of a nuclear fuel rod. Incident neutron beam ports are formed in a base unit that receives an incident filtered neutron beam. The ports aim the neutron beam at a periphery of the BWR fuel elements, which in the context of nuclear fuel rods includes zirconium alloy cladding. Collision of the neutrons with hydrogen in the cladding lowers their energy and scatters them at preferential angles. Scatter cavities defining scattered neutron paths are formed in the base unit, and absorber plates are disposed of terminal ends of the scatter cavities. The absorber plates become activated by resonance absorption from the neutrons scattered by hydrogen in the target fuel elements. The hydrogen content can be determined from the activated absorber plates.

Modified notched energy filter neutron radiography camera for

A method for fabricating a composite cladding comprised of a moderate-purity metal barrier of zirconium metallurgically bonded on the inside surface of a zirconium alloy tube which improves corrosion resistance. The improved corrosion resistance of the liner is accomplished by suitable heat treatment of the Zircaloy-zirconium composite cladding to allow diffusion of alloying elements, notably Fe and Ni, from the Zircaloy into the zirconium, in particular, to the inner surface of the zirconium liner. This diffusion anneal reduces the undesirable tendency of zirconium liner to oxidize rapidly.

Process for improving corrosion resistance of zirconium or zirconium

A cladding tube having a cross-section and including (1) a zirconium alloy outer circumferential substrate having an inner surface and having one or more alloying elements, (2) a zirconium barrier layer bonded to the inner surface of the outer circumferential substrate and being alloyed with the one or more alloying elements, and (3) a zirconium alloy inner circumferential liner bonded to the inner surface of the zirconium barrier layer. The barrier layer will have a concentration profile including a diffusion layer extending from the barrier layer's inner surface (facing nuclear fuel) to the barrier layer's interior (between the barrier layer's inner and outer surfaces). At the interior edge of the diffusion layer, there will be substantially no alloying elements. At the outer edge of the diffusion layer (the barrier layer's inner surface), the maximum concentration of alloying elements will occur.

Nuclear fuel cladding having an alloyed zirconium barrier layer

A method is provided for forming a three-layer cladding tube having an outer substrate, a zirconium barrier layer, and an inner liner having alloying elements, in which the zirconium barrier layer (located between an outer substrate and inner liner) is at least partially alloyed with alloying elements that impart resistance to corrosion. The barrier layer has a diffusion layer extending from its inner surface (facing the fuel) to the barrier layer's interior (the interior being defined between the barrier layer's inner and outer surfaces). At the interior edge of the diffusion layer, there will be substantially no alloying elements beyond those normally present in zirconium. The methods of forming such structure include a diffusion anneal of a three-layer cladding in the range of 650.degree.-1000.degree. C. for times between about 1 minute and 20 hours. This anneal drives some of the alloying elements from the inner liner into the zirconium barrier layer to form the diffusion layer. The exact time and temperature depends upon the fabrication stage at which the heat treatment occurs.

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San Jose, CA, United States of America

Daniel Reese Lutz