US3801734A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reactor-fuel assembly hold down
Assignee: Combustion Engineering Inc
•
Filing: 1971-12-23
•
Granted: 1974-04-02
•
Expires: 1991-12-23
Abstract
Abstract Vertical motion of nuclear reactor fuel element bundles is limited by tubular pistons which engage fuel assembly upper end fittings to thereby urge the fuel assemblies in the vertically downward direction. The tubular pistons are provided with mechanical stop means to limit their vertical motion and are disposed within guide tubes which extend between the reactor core fuel alignment plate and upper guide structure.
Inventors
- 👤 J West
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 02:23
CPC Classifications
G; G21; G21C; G21C7/00; G21C7/06; G21C7/08; G21C7/12; G21C7/16; G21C13/00; G21C13/02; G21C13/032; G21C13/036; G21C5/00; G21C5/02; G21C5/06; Y; Y02; Y02E; Y02E30/00; Y02E30/30
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
153 words
In a nuclear reactor having a core assembly including a fuel subassembly, the core assembly further comprising an upper guide structure support plate and a fuel subassembly alignment plate spacially displaced from and oriented substantially parallel to the support plate, the fuel subassembly comprising fuel element means positioned on the opposite side of the alignment plate from the support plate and having upper end fitting means, the improvement comprising fuel subassembly hold-down apparatus including: guidE tube means extending between and affixed to the support and alignment plates, said guide tube means axis being oriented substantially transversely of the planes defined by said plates and being coaxial with apertures provided in said plates; means movable within said guide tube means, said movable means contacting the end fitting means and cooperating therewith to hold the fuel element means down; and means for limiting the motion of said movable means axially of said guide tube means.
Claim 2
Dependent Claim
153 words
In a nuclear reactor having a core assembly including a fuel subassembly, the core assembly further comprising an upper guide structure support plate and a fuel subassembly alignment plate spacially displaced from and oriented substantially parallel to the support plate, the fuel subassembly comprising fuel element means positioned on the opposite side of the alignment plate from the support plate and having upper end fitting means, the improvement comprising fuel subassembly hold-down apparatus including: guidE tube means extending between and affixed to the support and alignment plates, said guide tube means axis being oriented substantially transversely of the planes defined by said plates and being coaxial with apertures provided in said plates; means movable within said guide tube means, said movable means contacting the end fitting means and cooperating therewith to hold the fuel element means down; and means for limiting the motion of said movable means axially of said guide tube means.
Claim 3
Dependent Claim
31 words
The apparatus of claim 1 wherein said movable means each comprise: cylinder means positioned in and coaxial with said guide tube means, said cylinder means extending upwardly from the support plate.
Claim 4
Dependent Claim
117 words
The apparatus of claim 2 wherein said motion limiting means comprises: a second apertured support plate, said second support plate being spacially displaced from and oriented substantially parallel to the upper guide structure support plate on the opposite side of the guide structure support plate from the alignment plate, the apertures in said second plate being greater in cross-sectional area than the cross-sectional area of said cylinder means, said cylinder means extending through said second plate means; and a pair of displaced and transversely extending flange means mounted on said cylinder means at opposite sides of said second plate, said flange means defining stops having areas greater than the areas of the apertures in said second plate.
Claim 5
Dependent Claim
57 words
The apparatus of claim 2 wherein the upper end fitting means have extensions which terminate in the vicinity of the alignment plate apertures, the extensions having outer contours, and wherein said cylinder means are provided with inner contours which cooperate with the end fitting extension outer contours to permit engagement of the end fittings by said cylinders.
Claim 6
Dependent Claim
34 words
The apparatus of claim 4 wherein the upper end fitting extensions terminate within the apertures in the alignment plate and are provided with stop means for limiting the upward movement of the fuel subassembly.
Claim 7
Dependent Claim
57 words
The apparatus of claim 3 wherein the upper end fitting means have extensions which terminate in the vicinity of the alignment plate apertures, the extensions having outer contours, and wherein said cylinder means are provided with inner contours which cooperate with the end fitting extension outer contours to permit engagement of the end fittings by said cylinders.
Claim 8
Dependent Claim
34 words
The apparatus of claim 6 wherein the upper end fitting extensions terminate within the apertures in the alignment plate and are provided with stop means for limiting the upward movement of the fuel subassembly.
Claim 9
Dependent Claim
52 words
The apparatus of claim 3 further comprising: spring means positioned between said second support plate and the one of said flange means which is mounted on the cylinder means between the second support and upper guide structure support plates, said spring means urging said cylinder means downwardly against the end fitting means.
Claim 10
Dependent Claim
52 words
The apparatus of claim 7 further comprising: spring means positioned between said second support plate and the one of said flange means which is mounted on the cylinder means between the second support and upper guide structure support plates, said spring means urging said cylinder means downwardly against the end fitting means.
Claim 11
Dependent Claim
33 words
The apparatus of claim 9 wherein the other of said flange means extends over and caps the upper end of said cylinder means, the lower contoured end of said cylinder means being open.
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) | 1977-04-01 | 1977-10-01 | 1978-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-01 | 1981-10-01 | 1982-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-01 | 1985-10-01 | 1986-04-02 | $7700.00 | Window Closed / Lapsed |