US3708559A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making nuclear fuel-containing bodies
Assignee: United Kingdom Atomic Energy Authority
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Filing: 1970-03-27
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Granted: 1973-01-02
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Expires: 1990-03-27
Abstract
Abstract In the forming of bodies, containing fission product retaining nuclear fuel particles, dispersed in a filler material, it is desirable to produce a compact and coherent body without any fractured fuel particles. Fractured particles occur during pressing and the risk of fracture may be reduced by overcoating the fuel particles with two layers of material which exhibit during pressing different rheological characteristics. The characteristics differ in that the inner layer is less readily deformable under the pressure than the outer layer which tends to flow into the spaces between the overcoated particles. On such deformation of the outer overcoating, the inner overcoating layer acts as a buffer between adjacent particles.
Inventors
- 👤 E Voice
- 👤 L Graham
- 👤 D Sturge
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 23:36
CPC Classifications
G; G21; G21C; G21C3/00; G21C3/42; G21C3/58; G21C3/62; G21C3/626; Y; Y02; Y02E; Y02E30/00; Y02E30/30
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
19 words
A method according to claim 1 wherein said inner and outer overcoating layers each comprise carbon particles and resin.
Claim 2
Dependent Claim
33 words
A method of making a body as claimed in claim 2 in which the differences in rheological characteristics are brought about by providing different proportions of the ingredients in the two overcoating layers.
Claim 3
Dependent Claim
40 words
A method as claimed in claim 2 in which the material of the overcoating layers comprises graphite powder impregnated with polymerizable resin, the material for the outer layer containing a higher proportion of resin than that for the inner layer.
Claim 4
Dependent Claim
28 words
A method as claimed in claim 2 in which the difference in rheological characteristics are brought about by providing different compositions of materials of the two overcoating layers.
Claim 5
Dependent Claim
24 words
A method as claimed in claim 5 in which the composition of the material for the outer layer includes a pressing lubricant or plasticizer.
Claim 6
Dependent Claim
33 words
A method as claimed in claim 2 in which the differences in rheological characteristics are brought about by providing both different ingredients and different proportions of ingredients in the inner and outer layers.
Claim 7
Dependent Claim
35 words
A method as claimed in claim 2 in which material for both inner and outer layers include a polymerizable resin, the inner layer being at least partially polymerized before the application of the outer layer.
Claim 8
Dependent Claim
73 words
A method as claimed in claim 8 in which the fission product retaining particles are coated with an inner overcoating layer of graphite powder and polymerizable resin, the inner layer being at least partially polymerized prior to the application of the second layer of similar overcoating material, the particles being pressed with the outer layer in the unpolymerized condition and then heated while the pressure is maintained to complete polymerization of the whole.
Claim 9
Dependent Claim
39 words
A method of making a body as claimed in claim 2 in which the overcoating materials comprises powdered graphite and polymerizable resin and the different rheological characteristics of the layers is brought about by the selection of the graphite.
Claim 10
Dependent Claim
47 words
A method of making a body as claimed in claim 10 in which the material for the inner layer of overcoating includes Gilsonite graphite powder and polymerizable resin and the material for the outer layer of overcoating includes graphite powder, derived from needle coke, and polymerizable resin.
Claim 11
Dependent Claim
33 words
A method of making a body as claimed in claim 2 in which the overcoating materials for the inner and outer layers comprise graphite powders of similar origin but of different grain size.
Claim 12
Dependent Claim
33 words
A method of making a body as claimed in claim 2 in which the material for the ouTer layer contains a higher proportion of pressing lubricant than the material for the outer overcoating.
Claim 13
Independent Claim
115 words
A method of making a pressed body comprising a mass of fission product retaining nuclear fuel particles dispersed in a matrix of graphitic material which process comprises applying to each particle an inner overcoating comprising powdered graphite and polymerizable resin, applying a second similar coating but having a higher resin content than the inner layer of a character which is more easily deformable under pressure than the inner layer, placing the overcoated particles in a die cavity, applying pressure to the particles while the die content is heated to soften the resin and than after pressing has deformed the outer layer of overcoating, polymerizing the whole of the unpolymerized resin while the pressure is maintained.
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) | 1976-01-02 | 1976-07-03 | 1977-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-02 | 1980-07-03 | 1981-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-02 | 1984-07-03 | 1985-01-02 | $7700.00 | Window Closed / Lapsed |