US4894203A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Nuclear fuel element having oxidation resistant cladding
Assignee: General Electric Co
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Filing: 1988-02-05
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Granted: 1990-01-16
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Expires: 2008-02-05
Abstract
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.
Inventors
- 👤 Ronald B. Adamson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 01:24
CPC Classifications
G; G21; G21C; G21C3/00; G21C3/02; G21C3/04; G21C3/16; G21C3/20; C; C22; C22C; C22C16/00; G21C3/06; Y; Y02; Y02E; Y02E30/00; Y02E30/30
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
142 words
An improved nuclear fuel element of the type including a zirconium alloy tube, a zirconium barrier layer metallurgically bonded to the inside surface of the alloy tube, and a central core of nuclear fuel material partially filling the inside of said tube so as to leave a gap between said sponge zirconium barrier and said nuclear fuel material, said improvement comprising an alloy layer formed on the inside surface of the zirconium barrier layer, said alloy layer being composed of one or more impurities present in a thin layer region of the zirconium barrier in amounts less than 1% by weight but sufficient to inhibit the oxidation of said inside surface of the zirconium barrier layer without substantially affecting the plastic properties of said barrier layer, wherein said impurities are selected from the group consisting of iron, chromium, copper, nitrogen, and niobium.
Claim 2
Dependent Claim
142 words
An improved nuclear fuel element of the type including a zirconium alloy tube, a zirconium barrier layer metallurgically bonded to the inside surface of the alloy tube, and a central core of nuclear fuel material partially filling the inside of said tube so as to leave a gap between said sponge zirconium barrier and said nuclear fuel material, said improvement comprising an alloy layer formed on the inside surface of the zirconium barrier layer, said alloy layer being composed of one or more impurities present in a thin layer region of the zirconium barrier in amounts less than 1% by weight but sufficient to inhibit the oxidation of said inside surface of the zirconium barrier layer without substantially affecting the plastic properties of said barrier layer, wherein said impurities are selected from the group consisting of iron, chromium, copper, nitrogen, and niobium.
Claim 3
Dependent Claim
59 words
An improved nuclear fuel element as in claim 1, wherein the zirconium alloy tube has a thickness in the range from about 500 to 1000 μm, the zirconium barrier layer has a thickness in the range from about 25 to 100 μm, and the thin layer region comprising alloy layer has a thickness from about 0.01 to 1.0 μm.
Claim 4
Dependent Claim
25 words
An improved nuclear fuel element as in claim 2, wherein at least one element is introduced by ion implantation, ion plating, or chemical vapor deposition.
Claim 5
Dependent Claim
66 words
An improved nuclear fuel element as in claim 2, wherein the elements are present in the alloy layer in the following amounts: niobium at 0.01 to 0.6 percent by weight; iron at 0.2 to 0.3 percent by weight; chromium at 0.05 to 0.3 percent by weight; iron and chromium mixture at 0.15 to 0.3 percent by weight; and copper at 0.02 to 0.2 percent by weight.
Claim 6
Dependent Claim
18 words
An improved nuclear fuel element as in claim 1, wherein the zirconium barrier layer is high purity zirconium.
Claim 7
Dependent Claim
16 words
An improved nuclear fuel element as in claim 1, wherein the zirconium barrier layer is zirconium.
Claim 8
Independent Claim
100 words
A method for treating a nuclear fuel composite cladding container to inhibit oxidation, said composite cladding container including a zirconium alloy tube and a zirconium barrier layer metallurgically bonded to the inner surface of the alloy tube, said method comprising introducing at least one impurity selected from the group consisting of iron, chromium, copper, nitrogen, and niobium into an inner surface of the zirconium barrier layer to form an alloy layer having increased oxidation resistance relative to said zirconium barrier, wherein no one of said impurities is present in an amount greater than 1% by weight in the alloy layer.
Claim 9
Independent Claim
100 words
A method for treating a nuclear fuel composite cladding container to inhibit oxidation, said composite cladding container including a zirconium alloy tube and a zirconium barrier layer metallurgically bonded to the inner surface of the alloy tube, said method comprising introducing at least one impurity selected from the group consisting of iron, chromium, copper, nitrogen, and niobium into an inner surface of the zirconium barrier layer to form an alloy layer having increased oxidation resistance relative to said zirconium barrier, wherein no one of said impurities is present in an amount greater than 1% by weight in the alloy layer.
Claim 10
Dependent Claim
66 words
A method as in claim 7, wherein the zirconium alloy tube has a thickness in the range from about 500 to 1000 μm, the zirconium barrier layer has a thickness in the range from about 25 to 100 μm, and wherein the impurities are introduced to a sufficient depth to form an alloy layer having a thickness in the range from about 0.01 to 1.0 μm.
Claim 11
Dependent Claim
20 words
A method as in claim 7, wherein the impurities are introduced by ion implantation, ion plating or chemical vapor deposition.
Claim 12
Dependent Claim
66 words
A method as in claim 7, wherein the impurities are introduced so as to form an alloy layer having the following composition: niobium at 0.01 to 0.6 percent by weight; iron at 0.2 to 0.3 percent by weight; chromium at 0.05 to 0.3 percent by weight; iron and chromium mixture at 0.15 to 0.3 percent by weight; and copper at 0.02 to 0.2 percent by weight.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1993-01-15 | 1993-07-17 | 1994-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-15 | 1997-07-17 | 1998-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-15 | 2001-07-17 | 2002-01-16 | $7700.00 | Window Closed / Lapsed |