US3920515A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fuel assembly for a nuclear reactor
Assignee: Westinghouse Electric Corp
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Filing: 1972-09-26
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Granted: 1975-11-18
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Expires: 1992-09-26
Abstract
Abstract A fuel assembly including multiple open channel grids for holding fuel rods and control rod guide thimbles in predetermined fixed relationship with each other. Metallic straps are interwoven to form a grid or egg crate configuration having openings which receive the fuel rods and guide thimbles. To properly support and cool the fuel rods near the grid-fuel rod interface, springs and dimples on the grid straps project into each opening, the dimples being oriented in a direction to permit flow of coolant upwardly therethrough. To minimize turbulence in coolant flow, the leading edge of each grid strap is provided with cutout sections which form scallops effective in channeling coolant in a uniform flow path through the network of grid openings.
Inventors
- 👤 Harry M Ferrari
- 👤 Douglas L Miller
- 👤 Long S Tong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:08
CPC Classifications
G; G21; G21C; G21C3/00; G21C3/30; G21C3/32; G21C3/322; G21C3/34; G21C3/356; G21C3/3563; Y; Y02; Y02E; Y02E30/00; Y02E30/30
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
218 words
A FUEL ASSEMBLY FOR A NUCLEAR REACTOR COMPRISING: AN ARRY OF FUEL RODS MOUNTED BETWEEN A BASE AND AN UPPER SUPPORT MEMBER; AT LEAST ONE OPEN CHANNEL GRID POSITIONED ON SAID ASSEMBLY FOR LATERALLY SUPPORTING AND HOLDING SAID FUEL RODS IN SPACED RELATIONSHIP WITH EACH OTHER; SAID OPEN CHANNEL GRID COMPRISING MULTIPLE STRAPS INTERWOVEN WITH EACH OTHER TO FORM A GRID OF EGG-CRATE COFIGURATION WHICH FORMS OPENINGS FOR RECEPTION OF SAID FUEL RODS; RESILIENT MEANS FORMED INTEGRAL WITH SAID STRAPS AND PROJECTING FROM ADJACENT STRAPS INTO EACH OPENING TO CONTACT A FUEL ROD THEREIN; RIGID MEAN PROJECTING FROM THE OTHER ADJACENT STRAPS INTO EACH OPENING TO CONTACT THE REMAINING SIDES OF SAID FUEL ROD AND IMPART LATERAL SUPPORT THERETO; EACH OF SAID RIGID MEANS COMPRISING SECTIONS OF A GRID STRAP DEFORMED INWARDLY TO FORM A DIMPLE HAVING AN OPENING EXTENDING AXIALLY OF SAID GRID SO THAT LIQUID COOLANT FLOWING THROUGH SAID GRID AND ALONG THE FUEL ROD LENGTH MOVES IN A SUBSTANTIALLY UNITERRUPTED PATH PAST SAID DIMPLES; AND MULTIPLE FIRST CUTOUT SECTIONS ON THE LEADING EDGES OF EACH SAID STRAPS DISPOSED ADJACENT TO AND IN AXIAL ALIGNMENT WITH EACH OF SAID RIGID MEANS TO, SAID MULTIPLE FIRST CUTOUT SECTIONS DEFINING A SERRATED CONFIGURATION HELP AVOID THE BUILD UP TO A BOUNDARY LAYER OF COOLANT AROUND EACH FUEL ROD.
Claim 2
Dependent Claim
218 words
A FUEL ASSEMBLY FOR A NUCLEAR REACTOR COMPRISING: AN ARRY OF FUEL RODS MOUNTED BETWEEN A BASE AND AN UPPER SUPPORT MEMBER; AT LEAST ONE OPEN CHANNEL GRID POSITIONED ON SAID ASSEMBLY FOR LATERALLY SUPPORTING AND HOLDING SAID FUEL RODS IN SPACED RELATIONSHIP WITH EACH OTHER; SAID OPEN CHANNEL GRID COMPRISING MULTIPLE STRAPS INTERWOVEN WITH EACH OTHER TO FORM A GRID OF EGG-CRATE COFIGURATION WHICH FORMS OPENINGS FOR RECEPTION OF SAID FUEL RODS; RESILIENT MEANS FORMED INTEGRAL WITH SAID STRAPS AND PROJECTING FROM ADJACENT STRAPS INTO EACH OPENING TO CONTACT A FUEL ROD THEREIN; RIGID MEAN PROJECTING FROM THE OTHER ADJACENT STRAPS INTO EACH OPENING TO CONTACT THE REMAINING SIDES OF SAID FUEL ROD AND IMPART LATERAL SUPPORT THERETO; EACH OF SAID RIGID MEANS COMPRISING SECTIONS OF A GRID STRAP DEFORMED INWARDLY TO FORM A DIMPLE HAVING AN OPENING EXTENDING AXIALLY OF SAID GRID SO THAT LIQUID COOLANT FLOWING THROUGH SAID GRID AND ALONG THE FUEL ROD LENGTH MOVES IN A SUBSTANTIALLY UNITERRUPTED PATH PAST SAID DIMPLES; AND MULTIPLE FIRST CUTOUT SECTIONS ON THE LEADING EDGES OF EACH SAID STRAPS DISPOSED ADJACENT TO AND IN AXIAL ALIGNMENT WITH EACH OF SAID RIGID MEANS TO, SAID MULTIPLE FIRST CUTOUT SECTIONS DEFINING A SERRATED CONFIGURATION HELP AVOID THE BUILD UP TO A BOUNDARY LAYER OF COOLANT AROUND EACH FUEL ROD.
Claim 3
Dependent Claim
17 words
A fuel assembly according to claim 1 wherein each of said cutout sections is of trapezoidal configuration.
Claim 4
Dependent Claim
83 words
The fuel assembly according to claim 1 wherein each rigid means on each of said other adjacent straps which extend into each opening are axially spaced from each other along the strap height and are located respectively at the leading edge and the trailing edge of said straps; and multiple second cutout sections formed in the trailing edge of each of said straps, each of said second cutout sections being located in axial alignment with said first cutout sections and said rigid means.
Claim 5
Dependent Claim
36 words
The Fuel assembly according to claim 1 wherein the upper and lower ends of the dimple of each rigid means are bent at an angle to the plane of the straps in which they are located.
Claim 6
Dependent Claim
143 words
The fuel assembly according to claim 1 wherein each strap contains axially extending slots which receive the body portion of adjacent straps thus permitting interweaving of the straps to form the egg crate openings, means on each strap in alignment with said slots for holding said straps in fixed relationship with each other, said means comprising tabs of strap material having ends which project outwardly from opposite sides of each strap, said tab ends being arranged to face each other and spaced a distance sufficient to receive the thickness of a strap which is interwoven therewith, and at least two pairs of said tabs spaced along the strap height, so that when the straps are interwoven, said pairs of tabs engage opposite sides of each strap placed in said slots to thereby hold said straps in immovable and fixed relationship with each other.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-17 | 1979-05-19 | 1979-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-17 | 1983-05-19 | 1983-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-17 | 1987-05-19 | 1987-11-18 | $7700.00 | Window Closed / Lapsed |