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US3761546A
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Method of making uranium dioxide bodies
Assignee: United States Atomic Energy Commission
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Filing: 1972-05-22
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Granted: 1973-09-25
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Expires: 1992-05-22
Abstract
Abstract Sintered uranium dioxide bodies having controlled density are produced from U3O8 and carbon by varying the mole ratio of carbon to U3O8 in the mixture, which is compressed and sintered in a neutral or slightly oxidizing atmosphere to form dense slightly hyperstoichiometric uranium dioxide bodies. If the bodies are to be used as nuclear reactor fuel, they are subsequently heated in a hydrogen atmosphere to achieve stoichiometry. This method can also be used to produce fuel elements of uranium dioxide plutonium dioxide having controlled density.
Inventors
- 👤 H Wilhelm
- 👤 Clusky J Mc
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:14
CPC Classifications
G; G21; G21C; G21C3/00; G21C3/42; G21C3/58; G21C3/62; G21C3/623; C; C01; C01G; C01G43/00; C01G43/01; C01G43/025; C01G56/00; C01G56/004; C01P; C01P2006/00; C01P2006/10; C01P2006/80; Y; Y02; Y02E; Y02E30/00; Y02E30/30
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
32 words
The method of claim 1 wherein the carbon is graphite and the U3O8 and graphite charge is pressed at a pressure of at least 10, 000 lbs/in2 to form a green body.
Claim 2
Dependent Claim
21 words
The method of claim 2 wherein the atmosphere is selected from the group consisting of argon, helium, nitrogen and carbon dioxide.
Claim 3
Dependent Claim
28 words
The method of claim 1 comprising the additional step of heating the uranium dioxide body in a hydRogen atmosphere, thereby completely reducing the body to stoichiometric uranium dioxide.
Claim 4
Dependent Claim
31 words
The method of claim 4 wherein the body is heated to a temperature above about 1,000* C. for a period of time sufficient to reduce the body to stoichiometric uranium dioxide.
Claim 5
Dependent Claim
12 words
The method of claim 5 wherein the body also contains plutonium dioxide.
Claim 6
Independent Claim
156 words
A method of making a uranium dioxide body for use in a fuel element wherein the body has a controlled final density of from about 77 to about 94 percent of the theoretical density comprising: mixing U3O8 with graphite in a ratio of 0.1 to 0.7 mole graphite to 1 mole of U3O8 to form a charge; the amount of graphite in the charge being determined by the desired final density; pressing the charge into a green body; heating the green body in a carbon dioxide atmosphere up to a temperature of 1, 350* to 1,500* C. for at least 2 hours whereby the U3O8 is reduced to hyperstoichiometric uranium dioxide and sintered; and heating the sintered body under a hydrogen atmosphere at a temperature of 1,350* to 1,500* C. for at least one-half hour, whereby said hyperstoichiometric uranium dioxide is reduced to stoichiometric uranium dioxide, thereby forming a uranium dioxide fuel element having controlled density.
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) | 1976-09-24 | 1977-03-26 | 1977-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-24 | 1981-03-26 | 1981-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-24 | 1985-03-26 | 1985-09-25 | $7700.00 | Window Closed / Lapsed |