Patent US3791466A successfully refreshed from Google Patents.
US3791466A
Expired / Lapsed
US
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Low parasitic capture fuel assembly structure
Assignee: Westinghouse Electric Corp
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Filing: 1972-03-21
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Granted: 1974-02-12
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Expires: 1992-03-21
Abstract
Abstract The basic fuel assembly structure for a nuclear reactor comprises a skeleton made up of individual hollow tubes composed of a zirconium base alloy, such as Zircaloy, and held in place by Inconel or stainless steel grids disposed between stainless steel end nozzles at the top and the bottom of the structure. The tubes serve as guide thimbles for cylindrical control elements strategically located in a square array of fuel rods held in place by spring fingers on the ''''egg-crate'''' grids. The guide thimbles are attached to the top and bottom nozzles and the grids by mechanical joints without welding dissimilar metals.
Inventors
- 👤 J Patterson
- 👤 E Bassler
- 👤 E Choby
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:13
CPC Classifications
G; G21; G21C; G21C3/00; G21C3/30; G21C3/32; G21C3/326; G21C3/33; G21C3/332; Y; Y02; Y02E; Y02E30/00; Y02E30/30
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
154 words
A fuel assembly for a nuclear reactor comprising an array of generally parallel elongated fuel elements, a plurality of elongated hollow tubular members containing control elements strategically located among the array of fuel elements, said tubular members being composed of a relatively low neutron capture metal, means separately attaching the opposite ends of said tubular members to top and bottom end nozzles respectively located at opposite ends thereof; at least one grid located between said end nozzles and formed by coacting straps which define multiple spaced openings through which the fuel elements and tubular members extend; a device immovably positioned on each of said tubular members, said device being located between said tubular means and the walls of said straps; and means securing said device to the inner walls of said straps which define the opening through which each tubular member extends, to thereby hold each tubular member in position in the fuel assembly.
Claim 2
Dependent Claim
154 words
A fuel assembly for a nuclear reactor comprising an array of generally parallel elongated fuel elements, a plurality of elongated hollow tubular members containing control elements strategically located among the array of fuel elements, said tubular members being composed of a relatively low neutron capture metal, means separately attaching the opposite ends of said tubular members to top and bottom end nozzles respectively located at opposite ends thereof; at least one grid located between said end nozzles and formed by coacting straps which define multiple spaced openings through which the fuel elements and tubular members extend; a device immovably positioned on each of said tubular members, said device being located between said tubular means and the walls of said straps; and means securing said device to the inner walls of said straps which define the opening through which each tubular member extends, to thereby hold each tubular member in position in the fuel assembly.
Claim 3
Dependent Claim
17 words
The fuel assembly defined in claim 1, wherein the device comprises a sleeve surrounding each tubular member.
Claim 4
Dependent Claim
35 words
The fuel assembly defined in claim 2, wherein each sleeve is composed of a metal similar to the metal of the grid straps, and the sleeve is secured to the grid straps by metallurgical bonding.
Claim 5
Dependent Claim
51 words
The fuel assembly defined in claim 3, wherein the grid straps are disposed at right angles to form generally square openings, and each sleeve has slots therein of a size sufficient to receive the straps during grid assembly to thereby hold the device and tubular member immovably in the grid straps.
Claim 6
Dependent Claim
50 words
The fuel assembly defined in claim 2, wherein spring means is secured to the inside surface of and along the length of said straps forming each opening, said spring means being positioned to bear against each tubular member and fuel element in the appropriate openings to prevent their lateral displacement.
Claim 7
Dependent Claim
30 words
The fuel assembly defined in claim 1, wherein each tubular member is deformed adjacent at least one end of said device to immovably fix the device on its tubular member.
Claim 8
Dependent Claim
33 words
The fuel assembly defined in claim 1, wherein the device is composed of a metal similar to the metal of the tubular members and is secured to the tubular members by metallurgical bonding.
Claim 9
Dependent Claim
21 words
The fuel assembly defined in claim 7, wherein the grid straps have recesses therein, and the device extends into said recesses.
Claim 10
Dependent Claim
71 words
The fuel assembly defined in claim 1, wherein said device comprises an adapter sleeve surrounding each tubular member extending through the top nozzle, said adapter sleeve having an external flange thereon, a retainer surrounding the adapter sleeve, said retainer having an internal flange engaging the external flange on the adapter slEeve, and a capture sleeve extending between the adapter sleeve and the retainer to engage the internal flange on the retainer.
Claim 11
Dependent Claim
79 words
The fuel assembly defined in claim 9, wherein the adapter sleeve and the capture sleeve are composed of a metal similar to the metal of the tubular member and the retainer is composed of a metal similar to the end nozzle, and wherein said adapter sleeve is secured to the tubular member by metallurgical bonding and the capture sleeve secured to the adapter sleeve by metallurgical bonding, and said retainer being secured to the end nozzle by metallurgical bonding.
Claim 12
Dependent Claim
70 words
The fuel assembly according to claim 1, wherein a plurality of grids are longitudinally spaced along the length of said tubular members, and the openings therein are in alignment for receiving the fuel elements and tubular members which bridge the space between said end nozzles; and the upper of said grids being located adjacent said top end nozzle and the lower of said grids located adjacent said bottom end nozzle.
Claim 13
Dependent Claim
65 words
The fuel assembly defined in claim 11, wherein the means separately attaching the tubular members to the top end nozzle comprises a sleeve on each tubular member metallurgically bonded to said nozzle; means securing each sleeve to each tubular member; and each sleeve on each tubular member being metallurgically bonded to the grid straps of the upper grid to hold the tubular members in position.
Claim 14
Dependent Claim
36 words
The fuel assembly according to claim 12, wherein the means securing the sleeve to said member comprises integrally formed protrusions on said tubular member which coact with the sleeve to prevent its displacement on said member.
Claim 15
Dependent Claim
66 words
The fuel assembly defined in claim 11, wherein the means separately attaching the tubular members to the bottom end nozzle comprises a sleeve on the bottom of each tubular member; a mechanical device connecting each sleeve to the bottom end nozzle; and each sleeve on each tubular means being metallurgically bonded to the grid straps of the lower grid to hold the tubular members in position.
Claim 16
Dependent Claim
35 words
The fuel assembly defined in claim 14, wherein said mechanical device includes a plug coacting with the walls of the tubular member and sleeve; and a coupler connecting the plug with the bottom end nozzle.
Claim 17
Dependent Claim
78 words
The fuel assembly according to claim 11, wherein extension means interconnects the outer portion of the upper grid with the top nozzle, and wherein the means attaching the tubular members to said top nozzle includes a close fit which permits axial movement of the tubular members therein; projections on said tubular members immediately abve and below said upper grid, said device on each tubular member being of a length sufficient to have its ends bear against said projections.
Claim 18
Dependent Claim
31 words
The fuel assembly according to claim 16, wherein each device includes an outwardly directed portion intermediate its length arranged to contact adjacent tubular members through openings in the grid strap walls.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-11 | 1977-08-13 | 1978-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-11 | 1981-08-13 | 1982-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-11 | 1985-08-13 | 1986-02-12 | $7700.00 | Window Closed / Lapsed |