Patent US3801452A successfully refreshed from Google Patents.
US3801452A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Nuclear reactor fuel elements
Assignee: United Kingdom Atomic Energy Authority
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Filing: 1970-08-21
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Granted: 1974-04-02
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Expires: 1990-08-21
Abstract
Abstract A fuel pin spacer grid has apertures through which the fuel pins extend. Each fuel pin bears against two pairs of longitudinally spaced stop members being biassed against the stop members by spring means acting on the fuel pin intermediate the pairs of stop members. The stop members are semi-resilient so as to allow small lateral deflections of the fuel pins but so as to become rigid to prevent greater lateral deflections of the fuel pins.
Inventors
- 👤 G Milburn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 08:04
CPC Classifications
G; G21; G21C; G21C3/00; G21C3/30; G21C3/32; G21C3/34; G21C3/344; Y; Y02; Y02E; Y02E30/00; Y02E30/30
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
165 words
In a nuclear reactor fuel element assembly including a plurality of elongate fuel pins supported in a bundle with their longitudinal axes parallel, a spacer grid structure, the grid structure being Of cellular form, having openings through which the fuel pins extend, said grid structure having at least two support members extending into each of said openings for supporting fuel pins laterally in the openings, the support members being longitudinally spaced with respect to the axis of the fuel pins and resilient means being provided extending into each of said openings in opposed relationship with said support members and located to engage with and bias the fuel pins into engagement with the support members, the support members comprising means for responding resiliently to small lateral deflections of the fuel pins arising from small forces acting on the fuel pins and becoming substantially rigid to prevent further deflection of the fuel pins under forces greater than a minimum defined by the resilience of the support members.
Claim 2
Dependent Claim
165 words
In a nuclear reactor fuel element assembly including a plurality of elongate fuel pins supported in a bundle with their longitudinal axes parallel, a spacer grid structure, the grid structure being Of cellular form, having openings through which the fuel pins extend, said grid structure having at least two support members extending into each of said openings for supporting fuel pins laterally in the openings, the support members being longitudinally spaced with respect to the axis of the fuel pins and resilient means being provided extending into each of said openings in opposed relationship with said support members and located to engage with and bias the fuel pins into engagement with the support members, the support members comprising means for responding resiliently to small lateral deflections of the fuel pins arising from small forces acting on the fuel pins and becoming substantially rigid to prevent further deflection of the fuel pins under forces greater than a minimum defined by the resilience of the support members.
Claim 3
Dependent Claim
29 words
A spacer grid structure as claimed in claim 1 wherein the resilient means are disposed to engage the fuel pins at a location between the longitudinally spaced support members.
Claim 4
Dependent Claim
109 words
A spacer grid structure as claimed in claim 1 wherein the support members have rigid stop portions which continuously engage the fuel pins, and resilient legs by means of which the support members are mounted in the openings of the grid structure, small lateral deflections of the fuel pins being accommodated by deflection of the resilient legs of the support members, lateral deflection of the fuel pins being limited by deflection of the resilient legs of the support members to the point where the rigid stop portions of the support members become effective in preventing further lateral deflection of the fuel pins in the openings of the grid structure.
Claim 5
Dependent Claim
118 words
A spacer grid structure as claimed in claim 3 comprising a cojoined layer of tubular ferrules, a first pair of laterally spaced support members at one level in each ferrule, a second similarly disposed pair of laterally spaced support members at another level in the ferrule, said resilient means comprising spring means disposed in opposed relationship to the support members in the ferrules to engage with and bias fuel pins extending through the ferrules into contact with the rigid stop portions of the support members, said spring means comprising a bow spring extending longitudinally in each ferrule and bearing on the fuel pins at a point intermediate the levels of the first and second pairs of support members.
References Cited (Backward Citations)
No citation records indexed.
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 |