US Patent No: 6,819,733
Number of patents in Portfolio can not be more than 2000
Fuel assembly and associated grid for nuclear reactor
Stats
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Nov 16, 2004
Issued date -
May 15, 2002
filing date -
10/147,215
serial no -
Expired
status
Importance
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Abstract
An improved grid for use in a fuel assembly of a nuclear reactor includes a plurality of straps that are interconnected with one another in a lattice fashion to define a plurality of cells, with the straps being configured to include a plurality of relatively more compliant springs and a plurality of relatively less compliant dimples, whereby each cell includes only one pair of springs and one pair of dimples disposed therein. The springs and dimples are contoured to engage a fuel rod or a thimble tube disposed within the cell. Each spring directly confronts one of the dimples to provide confronting pairs of features that engage the fuel rods or thimble tubes, with each cell including two pairs of confronting features. The ligaments of the springs and dimples extend in a direction generally perpendicular to the direction of coolant flow through the reactor in order to minimize pressure drop.
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First Claim
Related Publications
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International Classification(s)
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Cited Art
| Patent Info | (Count) | # Cites | Year |
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| 4,268,356 Nuclear reactor fuel assembly grid | 14 | 1978 | |
| 4,474,730 Nuclear fuel spacer grid | 19 | 1982 | |
| 4,521,374 Fuel grid with sleeves welded in notched grid straps | 15 | 1982 | |
| 4,578,240 Nuclear reactor fuel assembly spacer grid | 15 | 1983 | |
| 4,585,615 Nuclear fuel spacer grid with improved grid straps | 14 | 1983 | |
| 4,585,616 Nuclear fuel spacer grid with improved outer straps | 23 | 1983 | |
| 4,576,786 Partial grid for a nuclear reactor fuel assembly | 19 | 1983 | |
| 4,659,542 Grid structure for nuclear fuel assembly | 13 | 1984 | |
| 4,702,881 Nuclear reactor spacer grid | 22 | 1985 | |
| 4,659,541 Nuclear fuel rod support grid with improved multiple dimple arrangement | 11 | 1985 | |
| 4,678,632 Nuclear fuel assembly grid with predetermined grain orientation | 8 | 1985 | |
| 4,744,942 Nuclear reactor spacer grid loading | 11 | 1986 | |
| 4,803,043 Nuclear fuel rod grid spring and dimple structures | 23 | 1987 | |
| 4,895,698 Nuclear fuel rod grip with modified diagonal spring structures | 15 | 1988 | |
| 4,873,051 Nuclear fuel grid outer strap | 7 | 1988 | |
| 4,885,127 Nuclear fuel rod support grid with attachable spring and dimple support spacers | 15 | 1988 | |
| 4,957,697 Nuclear fuel rod support grid with generally S-shaped spring structures | 13 | 1988 | |
| 4,923,669 Nuclear fuel rod grid spring and dimple structures having chamfered edges for reduced pressure drop | 8 | 1989 | |
| 5,444,748 Grid structure for supporting fuel rods in a nuclear reactor | 13 | 1994 | |
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| 4,426,355 Spacer grid for nuclear fuel assembly | 14 | 1982 | |
| 5,331,678 Spacer grid rod support system | 2 | 1993 | |
| 5,440,599 Spacer grid with integral "side supported" flow directing vanes | 21 | 1994 | |
| 6,310,932 Fretting resistant spring design | 2 | 2000 | |
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| 4,594,216 Spacing grid for a nuclear reactor fuel element | 18 | 1982 | |
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| RE30247 Means for supporting fuel elements in a nuclear reactor | 6 | 1975 | |
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| 4,758,403 Grid with mixing fins for a nuclear fuel assembly | 16 | 1985 | |
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| 6,393,087 Duct-type spacer grid with swirl flow vanes for nuclear fuel assemblies | 8 | 1999 | |
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| 5,515,408 Fuel assembly | 8 | 1994 | |
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| 4,844,861 Fuel assembly for nuclear reactors | 10 | 1985 | |
Patent Citation Ranking
Maintenance Fees
| Fee | Large entity fee | small entity fee | micro entity fee | due date |
|---|---|---|---|---|
| 11.5 Year Payment | $7400.00 | $3700.00 | $1850.00 | May 16, 2016 |
| Fee | Large entity fee | small entity fee | micro entity fee |
|---|---|---|---|
| Surcharge - 11.5 year - Late payment within 6 months | $160.00 | $80.00 | $40.00 |
| Surcharge after expiration - Late payment is unavoidable | $700.00 | $350.00 | $175.00 |
| Surcharge after expiration - Late payment is unintentional | $1,640.00 | $820.00 | $410.00 |