Patent US4077838A successfully refreshed from Google Patents.
US4077838A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pyrolytic carbon-coated nuclear fuel
Assignee: United States Department of Energy
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Filing: 1976-07-28
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Granted: 1978-03-07
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Expires: 1996-07-28
Abstract
Abstract An improved nuclear fuel kernel having at least one pyrolytic carbon coating and a silicon carbon layer is provided in which extensive interaction of fission product lanthanides with the silicon carbon layer is avoided by providing sufficient UO 2 to maintain the lanthanides as oxides during in-reactor use of said fuel.
Inventors
- 👤 Terrence B. Lindemer
- 👤 Ernest L. Long, Jr.
- 👤 Ronald L. Beatty
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 13:57
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: 16
Claim 1
Independent Claim
68 words
In a spheroidal nuclear fuel paticle comprising a kernel of a fissile metal carbide and at least one pyrolytic carbon coating and a silicon carbide coating on or adjacent said kernel, the improvement comprising a metal oxide within said kernel at a concentration effective to maintain fission product lanthanides as oxides up to at least 75% FIMA, at a temperature of an operating nuclear reactor containing said particle.
Claim 2
Dependent Claim
68 words
In a spheroidal nuclear fuel paticle comprising a kernel of a fissile metal carbide and at least one pyrolytic carbon coating and a silicon carbide coating on or adjacent said kernel, the improvement comprising a metal oxide within said kernel at a concentration effective to maintain fission product lanthanides as oxides up to at least 75% FIMA, at a temperature of an operating nuclear reactor containing said particle.
Claim 3
Dependent Claim
30 words
The particle of claim 1 in which the kernel is a dispersion of fissile metal carbide and an effective concentration of said metal oxide within a carbon or graphite matrix.
Claim 4
Dependent Claim
14 words
The particle of claim 2 in which the metal oxide is UO 2 .
Claim 5
Dependent Claim
19 words
The particle of claim 3 in which the UO 2 comprises 30 to 85 mole percent of said kernel.
Claim 6
Dependent Claim
45 words
The fuel particlee of claim 2 in which said metal carbide is selected from the group consisting of uranium carbide, thorium carbide and plutonium carbide and the effective concentration of said metal oxide is selected from the group consisting of uranium oxide and plutonium oxide.
Claim 7
Dependent Claim
48 words
The fuel particle of claim 4 in which the concentration of said oxide is at a concentration effective to establish a thermodynamic equilibrium with said carbon or graphite to maintain a CO and CO 2 particle pressure less than 10.sup.(6.8-13,300/T° K.) atmospheres at a temperature above 1350 K.
Claim 8
Dependent Claim
29 words
The particle of claim 1 in which the fissile metal carbide is UC 2 and said kernel comprises 25-80 mole percent UC 2 and the balance UO 2 .
Claim 9
Independent Claim
76 words
A method of preventing lanthanide fission product interaction with coating materials in a spheroidal nuclear fuel particle comprising a kernel containing a fissile metal carbide and at least one pyrolytic carbon coating and a silicon carbide coating on or adjacent said kernel said method comprising providing sufficient metal oxide within said kernel to maintain fission product lanthanides as oxides up to at least 75% FIMA, at a temperature of an operating nuclear reactor containing said particle.
Claim 10
Independent Claim
76 words
A method of preventing lanthanide fission product interaction with coating materials in a spheroidal nuclear fuel particle comprising a kernel containing a fissile metal carbide and at least one pyrolytic carbon coating and a silicon carbide coating on or adjacent said kernel said method comprising providing sufficient metal oxide within said kernel to maintain fission product lanthanides as oxides up to at least 75% FIMA, at a temperature of an operating nuclear reactor containing said particle.
Claim 11
Dependent Claim
14 words
The method of claim 8 in which the metal oxide is UO 2 .
Claim 12
Dependent Claim
29 words
The method of claim 9 in which the fissile metal carbide is UC 2 and said UC 2 comprises 25-80% of said kernel and the balance UO 2 .
Claim 13
Dependent Claim
30 words
The method of claim 8 in which the kernel is a dispersion of fissile metal carbide and an effective concentration of said metal oxide within a carbon or graphite matrix.
Claim 14
Dependent Claim
26 words
The method of claim 11 in which the metal oxide is UO 2 and said UO 2 comprises 30 to 85 mole percent of said kernel.
Claim 15
Dependent Claim
44 words
The method of claim 8 in which said metal carbide is selected from the group consisting of uranium carbide, thorium carbide, and plutonium carbide, and the effective concentration of said metal oxide is selected from the group consisting of uranium oxide and plutonium oxide.
Claim 16
Dependent Claim
46 words
The method of claim 11 in which the concentration of said oxide is at concentration effective to establish a thermodynamic equilibrium with said carbon or graphite to maintain a CO and CO 2 particle pressures less than 10.sup.(6.8-13.300/T° K.) atmospheres at a temperature above 1350 K.
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) | 1981-03-06 | 1981-09-05 | 1982-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-03-06 | 1985-09-05 | 1986-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-03-06 | 1989-09-05 | 1990-03-07 | $7700.00 | Window Closed / Lapsed |