US3625822A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Nuclear reactors and to fuel element assemblies for use therein
Assignee: Central Electricity Generating Board
•
Filing: 1968-05-16
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Granted: 1971-12-07
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Expires: 1988-05-16
Abstract
Abstract A fuel element assembly for location in a fuel channel of a nuclear reactor, through which channel coolant is passed longitudinally, comprises a cluster of fuel pins arranged parallel to one another but spaced apart so as to leave a free coolant passage extending completely around each pin for generally longitudinal flow. Some of the pins have multistart helical ribs with a left-handed helix and some have multistart helical ribs with a right-handed helix to impart transverse components to the longitudinal flow in a predetermined pattern to improve the heat transfer from the fuel elements to the coolant.
Inventors
- 👤 Paul Langford Mantle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:32
CPC Classifications
G; G21; G21C; G21C3/00; G21C3/30; G21C3/32; G21C3/322; G21C3/324; Y; Y02; Y02E; Y02E30/00; Y02E30/30
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
17 words
A fuel element assembly as claimed in claim 1 wherein the ribs are formed as multistart helices.
Claim 2
Dependent Claim
21 words
A fuel element assembly as claimed in claim 1 wherein the ribs are formed integrally with a can containing fuel material.
Claim 3
Dependent Claim
23 words
A fuel element assembly as claimed in claim 1 wherein the ribs are formed by wrapping wire around a can containing fuel material.
Claim 4
Dependent Claim
18 words
A fuel element as claimed in claim 1 wherein the pins have smooth cylindrical surfaces between the ribs.
Claim 5
Dependent Claim
17 words
A fuel element assembly as claimed In claim 1 wherein the helix angle is greater than 10*.
Claim 6
Dependent Claim
18 words
A fuel element assembly as claimed in claim 1 wherein the helix angle is between 30* and 40*.
Claim 7
Dependent Claim
128 words
A fuel element assembly comprising a plurality of fuel pins arranged parallel to one another but spaced apart leaving a free space around each pin for the axial flow of a coolant, some of the pins having helical ribs with a left-handed helix and others of the pins having helical ribs with a right-handed helix, the spacing apart of the pins being such that there is free space for axial flow outside the ribs all around the pins, the pins with the left- and right-handed ribs defining transverse gas flow paths around groups of pins, each path having on one side of the path a plurality of pins all with left-handed helices and on the other side of the path a plurality of pins all with right-handed helices.
Claim 8
Dependent Claim
46 words
A fuel element assembly as claimed in claim 8 wherein the fuel pins are arranged in a circular pattern, all the pins in one circle having helical ribs of one sense, and all the pins in immediately adjacent circles having helical ribs of the opposite sense.
Claim 9
Dependent Claim
51 words
A fuel element assembly as claimed in claim 8 wherein the fuel pins are arranged with pins having left-handed ribs on one side and pins having right-handed ribs on the other side of radial paths to impart radial inward motion and radial outward motion of the coolant in separate radial paths.
Claim 10
Dependent Claim
26 words
A fuel element assembly as claimed in claim 10 wherein the pins are arranged to provide radially inward and radially outward paths alternately around the cluster.
Claim 11
Dependent Claim
49 words
A fuel element assembly as claimed in claim 8 wherein the fuel pins are arranged with pins having left-handed ribs on one side and pins having right-handed ribs on the other side of paths extending around groups of pins to impart circular motion of the coolant around the groups.
Claim 12
Dependent Claim
68 words
A fuel element assembly as claimed in claim 8 wherein the fuel pins are arranged with pins having left-handed ribs on one side and pins having right-handed ribs on the other side of paths extending in substantially parallel directions across the coolant channel to impart transverse movement to the coolant along these paths, the arrangement being such that the transverse movement is in opposite directions along alternate paths.
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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) | 1974-12-06 | 1975-06-07 | 1975-12-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-06 | 1979-06-07 | 1979-12-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-06 | 1983-06-07 | 1983-12-07 | $7700.00 | Window Closed / Lapsed |