US4264540A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of nuclear fuel pellets
Assignee: British Nuclear Fuels Ltd
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Filing: 1979-05-08
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Granted: 1981-04-28
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Expires: 1999-05-08
Abstract
Abstract In the production of nuclear fuel pellets consisting essentially of oxides of uranium, or mixtures of these oxides with oxides of thorium or plutonium, by granulating the oxide powder, pressing the granulated powder into compacts and sintering the compacts, niobium pentoxide is added to the oxide power in sufficient quantity to encourage grain growth in the oxide compact during sintering and the sintering and other process parameters are adjusted so that no impurities are trapped in the sintering pellets which would prevent a high matrix density and grain size being obtained. Adjustment and control of the oxygen potential of the sintering atmosphere is proposed.
Inventors
- 👤 Gregg G. Butler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 13:21
CPC Classifications
G; G21; G21C; G21C3/00; G21C3/42; G21C3/58; G21C3/62; G21C3/623; Y; Y02; Y02E; Y02E30/00; Y02E30/30
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
81 words
The production of nuclear fuel pellets consisting essentially of oxides of uranium, or mixtures of these oxides with oxides of thorium or plutonium, formed into compacts and sintered wherein niobium pentoxide is included in the oxide compact in sufficient quantity to encourage grain growth in the oxide compact during sintering, and the sintering and other process parameters are adjusted so that no impurities are trapped in the sintering pellets which would prevent a high matrix density and grain size being obtained.
Claim 2
Dependent Claim
81 words
The production of nuclear fuel pellets consisting essentially of oxides of uranium, or mixtures of these oxides with oxides of thorium or plutonium, formed into compacts and sintered wherein niobium pentoxide is included in the oxide compact in sufficient quantity to encourage grain growth in the oxide compact during sintering, and the sintering and other process parameters are adjusted so that no impurities are trapped in the sintering pellets which would prevent a high matrix density and grain size being obtained.
Claim 3
Dependent Claim
24 words
The production of nuclear fuel pellets as claimed in claim 1 wherein the compacts are sintered in an atmosphere having a controlled oxygen potential.
Claim 4
Dependent Claim
41 words
The production of nuclear fuel pellets as claimed in claim 2 wherein the atmosphere is hydrogen containing at least 1000 parts per million by volume and not more than 9000 parts per million by volume of water vapour or carbon dioxide.
Claim 5
Dependent Claim
32 words
The production of nuclear fuel pellets as claimed in claim 1 wherein the quantity of niobium pentoxide added is between 0.2% and 0.6% by weight of the weight of the oxide powder.
Claim 6
Dependent Claim
34 words
The production of nuclear fuel pellets as claimed in claim 4 characterised in that the quantity of niobium pentoxide added is between 0.3% and 0.5% by weight of the weight of the oxide powder.
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) | 1984-04-27 | 1984-10-27 | 1985-04-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-04-27 | 1988-10-27 | 1989-04-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-04-27 | 1992-10-27 | 1993-04-28 | $7700.00 | Window Closed / Lapsed |