US4094738A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Nuclear fuel pellet design to minimize dimensional changes
Assignee: Westinghouse Electric Corp
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Filing: 1976-05-19
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Granted: 1978-06-13
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Expires: 1996-05-19
Abstract
Abstract An improved nuclear fuel composition characterized as a mixture of the dioxide of uranium and plutonium with pores of specified sizes and volumes of each size. The volume of pores of each size are adjusted so that as each group of pores of each size is removed by the nuclear fission induced process of densification, the volume removed is balanced by the volume added by the nuclear fission induced process of solid state swelling. This fuel composition is dimensionally stable in-pile to high burnups because the rate of pore removal is matched to the rate of swelling.
Inventors
- 👤 Walston Chubb
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 06:30
CPC Classifications
G; G21; G21C; G21C3/00; G21C3/42; G21C3/58; G21C3/62; G21C3/623; Y; Y02; Y02E; Y02E30/00; Y02E30/30; Y10; Y10S; Y10S376/00; Y10S376/90; Y10S376/901
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
84 words
A nuclear fuel pellet for use in a nuclear reactor, said fuel pellet consisting essentially of uranium dioxide and plutonium dioxide and having pores therein randomly distributed to provide a balance between pellet swelling and pore removal at a plurality of temperatures less than 1000° C, said pores being less than 1 percent of the total pellet volume for pore sizes less than 2 microns, and up to 6 percent of total pellet volumes for pore sizes between 0 microns and about 20 microns.
Claim 2
Dependent Claim
84 words
A nuclear fuel pellet for use in a nuclear reactor, said fuel pellet consisting essentially of uranium dioxide and plutonium dioxide and having pores therein randomly distributed to provide a balance between pellet swelling and pore removal at a plurality of temperatures less than 1000° C, said pores being less than 1 percent of the total pellet volume for pore sizes less than 2 microns, and up to 6 percent of total pellet volumes for pore sizes between 0 microns and about 20 microns.
Claim 3
Dependent Claim
77 words
The pellet according to claim 1 wherein the pore sizes between 0 and 20 microns includes pores whose diameter are (a) in the range of 2 to 7 microns and constitutes up to two percent of total pellet volume, (b) in the range of 7 to 12 microns and constitutes up to two percent of total pellet volume, and (c) in the range of 2 to 12 microns and constitutes 1 to 3 percent of total volume.
Claim 4
Dependent Claim
34 words
The pellet according to claim 2 wherein the pore sizes between 0 and 20 microns includes pores whose diameter ranges between 2 and 15 microns, constitutes 2 to 4 percent of total pellet volume.
Claim 5
Dependent Claim
34 words
The pellet according to claim 3 wherein the pore sizes between 2 and 40 microns includes pores whose diameter ranges between 15 and 20 microns constitutes 1 to 3 percent of total pellet volume.
Claim 6
Dependent Claim
51 words
The pellet according to claim 1 wherein the pore sizes between 2 and 40 microns includes pore size groups 2 to 7 microns, 7 to 12 microns, 12 to 15 microns, 15 to 18 microns, and 18 to 20 microns, with 1 percent porosity in each of said pore size groups.
Claim 7
Dependent Claim
29 words
The pellet according to claim 5 which further includes a pore size of 20 to 40 microns, which group alone constitutes up to 5 percent of total pellet volume.
Claim 8
Dependent Claim
33 words
The pellet according to claim 5 wherein the pore volumes in all the pore size groups up to 20 microns is no more than 6 volume percent nor less than 4 volume percent.
References Cited (Backward Citations)
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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) | 1981-06-12 | 1981-12-12 | 1982-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-12 | 1985-12-12 | 1986-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-12 | 1989-12-12 | 1990-06-13 | $7700.00 | Window Closed / Lapsed |